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Home > Plant Care Guide > Common St. John's Wort

How to Care for Common St. John's Wort

Common St. John's wort (*Hypericum perforatum*) is a plant species that is native to Europe and Central Asia. Common St. John's wort is considered poisonous to livestock and can cause problems for humans if consumed. This dense, fast-growing plant has been introduced to North America and Australia, where it is often viewed as an invasive species.

Symbolism

Animosity, superstition

Water

Every week

Sunlight

Full sun

Basic Care Guide

Water

Common St. John's wort can withstand drought but is intolerant of waterlogged soil. In the first year after planting, about 2.5 cm of water every week will be enough. In areas with plentiful rain, no additional watering is needed. From the second year on, common St. John's wort doesn't need any additional watering, as normal precipitation will meet its needs for water. If over-watered, its roots are likely to rot due to waterlogging, and leaves will wither and dry up.

Potted Common St. John's wort

If your plant is in a pot. The most precise way to decide whether your Common St. John's wort needs water is to plunge your finger into the soil. If you notice that the first two to three inches of soil have become dry, it is time to add some water. When it comes time to water your Common St. John's wort , you should not be shy about how much water you give. With the first two to three inches of soil dry, this plant will appreciate a long and thorough watering. Supply enough water to soak the soil entirely. The amount of water you add should be enough to cause excess water to flow through the drainage holes at the bottom of your pot. If you don’t see excess water draining from the pot, you have likely underwatered your plant. But do not let the water accumulate inside the soil, which will be very dangerous to the plant as well. Alternatively, a lack of water draining through the pot could indicate poorly draining soils, which is detrimental to the health of this plant and should be avoided.

The Common St. John's wort plant will have its highest water needs during the hottest months of the year. During the height of summer, you may need to give this plant water more than once per week, depending on how fast the soil dries out. The opposite is true during the winter. In winter, your plant will enter a dormant phase, in which it will need far less water than usual. In fact, you may not need to water this plant at all during the winter months. However, if you do water during winter, you should not do so more than twice per month. Watering too much at this time will make it more likely that your Common St. John's wort will contract a disease.

Ground Common St. John's wort

If you grow your Common St. John's wort outdoors in the ground, you can use a similar method to test the soil. Again, when you find that the first few inches of soil have dried out, it is time to add water. During the spring and early fall, this method will often lead you to water this plant about once every week. When extremely hot weather arrives, you may need to increase your watering frequency to about twice or more per week. With that said, mature, well-established Common St. John's wort can show an admirable ability to withstand drought.

The water needs of the Common St. John's wort can change depending on growth stages as well. For example, when your Common St. John's wort is in the first few years of its life, or if you have just transplanted it to a new growing location, you will need to give more water than usual. During both of those stages, your Common St. John's wort will put a lot of energy towards sprouting new roots that will then support future growth. For those roots to perform their best, they need a bit more moisture than they would at a more mature phase. After a few seasons, your Common St. John's wort will need much less water. Another growth stage in which this plant may need more water is during the bloom period. Flower development can make use of a significant amount of moisture, which is why you might need to give your Common St. John's wort more water at this time.

Overwater and underwater

Underwatering is far less common for the Common St. John's wort , as this plant has decent drought tolerance. However, underwatering remains a possibility, and when it occurs, you can expect to find that the leaves of your Common St. John's wort have become brittle and brown.

It is crucial that you notice the signs of overwatering as soon as possible when caring for an Common St. John's wort plant. Some of the diseases that arise from overwatering, such as root rot, may not be correctable if you wait too long. If you see early signs of overwatering, you should reduce your watering schedule immediately. You may also want to assess the quality of soil in which your Common St. John's wort plant grows. If you find that the soil drains very poorly, you should replace it immediately with a loose, well-draining potting mix. On the other hand, if you find signs that your Common St. John's wort is receiving too little water, all you need to do is water more regularly until those signs have subsided.

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What is the best way to water my Common St. John's wort?

When watering the Common St. John's wort, you should aim to use filtered water that is at room temperature. Filtered water is better for this plant, as tap water can contain particles that are harmful to its health. The reason that the water should be at room temperature or slightly warmer is that the Common St. John's wort comes from a warm environment, and cold water can be somewhat of a shock to its system. Also, you should avoid overhead watering for this plant, as it can cause foliage complications. Instead, simply apply your filtered room temperature water to the soil until the soil is entirely soaked. Soaking the soil can be very beneficial for this plant as it moistens the roots and helps them continue to spread through the soil and collect the nutrients they need.

What should I do if I water my Common St. John's wort too much or too little?

Both overwatering and underwatering will be detrimental to the health of your Common St. John's wort, but overwatering is a far more common issue. When this species receives too much water, its stems and leaves may begin to wilt and turn from green to yellow. Overwatering over a prolonged period may also lead to diseases such as root rot, mold, and mildew, all of which can kill your plant. Underwatering is far less common for the Common St. John's wort, as this plant has decent drought tolerance. However, underwatering remains a possibility, and when it occurs, you can expect to find that the leaves of your Common St. John's wort have become brittle and brown.

It is crucial that you notice the signs of overwatering as soon as possible when caring for your Common St. John's wort. Some of the diseases that arise from overwatering, such as root rot, may not be correctable if you wait too long. If you see early signs of overwatering, you should reduce your watering schedule immediately. You may also want to assess the quality of soil in which your Common St. John's wort grows. If you find that the soil drains very poorly, you should replace it immediately with a loose, well-draining potting mix. On the other hand, if you find signs that your Common St. John's wort is receiving too little water, all you need to do is water more regularly until those signs have subsided.

How often should I water my Common St. John's wort?

If you grow your Common St. John's wort outdoors in the ground, you can use a similar method to test the soil. Again, when you find that the first few inches of soil have dried out, it is time to add water. During the spring and early fall, this method will often lead you to water this plant about once every week. When extremely hot weather arrives, you may need to increase your watering frequency to about twice or more per week. With that said, mature, well-established the Common St. John's wort can show an admirable ability to withstand drought.

How much water does my Common St. John's wort need?

When it comes time to water your Common St. John's wort, you should not be shy about how much water you give. With the first two to three inches of soil dry, this plant will appreciate a long and thorough watering. Supply enough water to soak the soil entirely. The amount of water you add should be enough to cause excess water to flow through the drainage holes at the bottom of your pot. If you don’t see excess water draining from the pot, you have likely underwatered your plant. But do not let the water accumulate inside the soil, which will be very dangerous to the plant as well. Alternatively, a lack of water draining through the pot could indicate poorly draining soils, which is detrimental to the health of this plant and should be avoided. If the plant is outside, 1 inch of rain per week will be sufficient.

How should I water my Common St. John's wort at different growth stages?

How should I water my Common St. John's wort through the seasons?

The Common St. John's wort will have its highest water needs during the hottest months of the year. During the height of summer, you may need to give this plant water more than once per week, depending on how fast the soil dries out. The opposite is true during the winter. In winter, your plant will enter a dormant phase, in which it will need far less water than usual. In fact, you may not need to water this plant at all during the winter months. However, if you do water during winter, you should not do so more than about once per month. Watering too much at this time will make it more likely that your Common St. John's wort will contract a disease.

What's the difference between watering my Common St. John's wort indoors and outdoors?

It is most common to grow the Common St. John's wort indoors for any gardener that does not live in temperate and tropical regions. Those gardeners should consider the fact that soil in a container can dry out a bit faster than ground soil. Also, the presence of drying elements such as air conditioning units can cause your Common St. John's wort to need water on a more frequent basis as well. if you planted it outside. When that is the case, it’s likely you won’t need to water your Common St. John's wort very much at all. If you receive rainfall on a regular basis, that may be enough to keep your plant alive. Alternatively, those who grow this plant inside will need to water it more often, as allowing rainwater to soak the soil will not be an option.

Fertilizer

Common St. John's wort requires very little fertilizing. Usually, no additional fertilization is needed after the initial planting, unless obvious symptoms of slow growth appear. If that happens, apply some low-concentration balanced compound fertilizer (10-10-10 NPK ratio).

Common St. John's wort grow throughout many regions of the world and are often some of the best plants to use for foliage gardens. If you want to reap the full benefits of growing a Common St. John's wort, in your garden, you should understand the basics of its care routine, with special consideration for fertilization. The information below will answer some of the most important questions related to fertilizing a Common St. John's wort.

The leaves of the Common St. John's wort comprise most of its main structure, and fertilization is one of the most impactful ways that you can ensure that those leaves look great while also serving their function. Proper fertilization will help your Common St. John's wort hold leaves with consistent color and a healthy texture. Fertilization also works below the soil's surface to help your Common St. John's wort generate new roots and maintain the roots that are already part of the root system. This means that fertilization will not just keep your plant healthy now, but it will also help your plant be better capable of absorbing soil nutrients in the future.

If you grow your Common St. John's wort outdoors each year, this perennial plant will send new growth shooting out in early spring. The emergence of those leaves is a sign that the time is right to begin fertilization for the year. Often, a Common St. John's wort will perform just fine with a single application of fertilizer when the spring arrives. However, if you wish to maximize the growth of your Common St. John's wort, you can repeat the feeding multiple times throughout the spring and early summer. If you choose this route, you can feed your Common St. John's wort about once every month to a month and a half.

Fortunately, choosing the best fertilizer for a Common St. John's wort is a very straightforward task. These plants will thrive on a general-purpose garden fertilizer that has equal amounts of nitrogen, phosphorus, and potassium. A fertilizer that has a ratio of 10-10-10 or something similar will be very effective. When in doubt, be sure to avoid fertilizers that have high amounts of nitrogen.

Most of the best fertilizer for a Common St. John's wort will come in a granular form. These fertilizers should be slow-release and will be very easy to apply to the soil. It can also be helpful to feed your Common St. John's wort using an organic soil amendment such as compost.

Wait until your Common St. John's wort has just barely poked its first leaves through the soil's surface in early spring. Once you see that sign, apply a granular slow-release fertilizer with a balanced formula to the soil that surrounds the base of your Common St. John's wort. You can repeat a similar process later in the season if you choose. When reapplying fertilizer to a Common St. John's wort, you should, again, apply the fertilizer to the soil at the base of the plant rather than to the plant itself. At times, this may require you to move some leaves out of the way to access the soil above the roots. It's also often a good choice to water your Common St. John's wort before and after you feed it.

The Common St. John's wort doesn't necessarily need to receive high volumes of fertilizer each year, which means overfertilization is entirely possible. If you overfertilize your Common St. John's wort, you will likely notice first that the leaves have turned brown.

Overfertilization of Common St. John's wort is especially common if you use a fertilizer that has higher concentrations of nitrogen. High nitrogen content will likely cause the leaves of your Common St. John's wort to become discolored, lose much of their moisture, and begin curling at the margins. Many gardeners avoid such complications by limiting fertilization of their Common St. John's wort to once per year in early spring.

In the late fall and winter, your Common St. John's wort will enter a dormant phase in which it will no longer produce new growth. At this time, you should avoid fertilizing your Common St. John's wort. If you choose to fertilize multiple times during spring and summer, you should begin reducing your fertilization rate as summer approaches, as your Common St. John's wort 's growth rate will also slow.

Overall, it is never a wise choice to fertilize your Common St. John's wort during times when the weather is unseasonably hot or when the soil is extraordinarily dry. Fertilizing in either of those cases can stress your Common St. John's wort and cause it to perish prematurely.

Why do I need to fertilize my Common St. John's wort?

Fertilization also works below the soil's surface to help your Common St. John's wort generate new roots and maintain the roots that are already part of the root system. This means that fertilization will not just keep your plant healthy now, but it will also help your plant be better capable of absorbing soil nutrients in the future.

When is the best time to fertilize my Common St. John's wort?

Often, a Common St. John's wort will perform just fine with a single application of fertilizer when the spring arrives. However, if you wish to maximize the growth of your Common St. John's wort, you can repeat the feeding multiple times throughout the spring and early summer. If you choose this route, you can feed your Common St. John's wort about once every month to a month and a half.

When should I avoid fertilizing my Common St. John's wort?

What type of fertilizer does my Common St. John's wort need?

How do I fertilize my Common St. John's wort?

You can repeat a similar process later in the season if you choose. When reapplying fertilizer to a Common St. John's wort, you should, again, apply the fertilizer to the soil at the base of the plant rather than to the plant itself. At times, this may require you to move some leaves out of the way to access the soil above the roots. It's also often a good choice to water your Common St. John's wort before and after you feed it.

What happens if I fertilize my Common St. John's wort too much?

Sunlight

Common St. John's wort needs sufficient sunlight but doesn't tolerate direct light. Grow the plant in the shade of other plants or on a balcony away from strong, hard light. Expose it to more sunlight in the spring and fall to help it grow, but in the summer, place the potted plants in half-shaded places and mist them with water to cool the temperature and increase humidity. Otherwise, symptoms like drying leaf tips may appear.

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What type of sunlight does Common St. John's wort need?

Common St. John's wort needs full sun every day, and these plants rely on a minimum of six hours of sunlight to keep their leaves, roots, and blooms in a healthy state. Even though most perennials need six hours of sunlight a day, plants like the Orange Daylily or Giant Coreopsis could live off less sun for a minimum of three hours daily. Even though these perennial flowering plants can live with only three hours of direct sunlight, they won't be able to thrive like they would in sunnier conditions.

Can sunlight damage Common St. John's wort? How to protect Common St. John's wort from the sun and heat damage?

The few Perennial Flowering Plants that don't like excessive heat in warm climates might react poorly to too much sun if they have heat damage. These plants may wilt or dry out from too much sun and may also develop growth issues if they're regularly in the sun during the most intense heat of the day. Some plants don't need protection from the light afternoon sun, but those that are harmed by intense afternoon exposure should be provided some shade in warmer climates. Gardeners could give these plants plenty of shade by planting them in spots that don't receive direct heat during the afternoon, like under trees or behind bushes.

Should I protect Common St. John's wort from sun exposure?

While many perennial plants need plenty of sun to bloom to their fullest extent, some of them benefit from less sun in warmer climates. For example, people who live in hotter climates might want to provide shade for their flowering perennials in the hot afternoon sun, and this is even more true for months in the summer.

Even though some perennial flowering plants will benefit from partially shaded in the hottest climates, plants like the Giant Coreopsis aren't intimidated by too much sun. They might sit outside in the full sun in hot weather and still thrive.

What will happen if Common St. John's wort gets inadequate sunlight?

If you're growing Common St. John's wort and you aren't getting enough sunlight, you'll notice signs of inadequate requirements in your plants. Most plants won't produce as many blooms as they would if they had full sun exposure. Some plants will develop dry spots on their leaves, but most of these plants will still bloom in the inadequate sun. Even though they bloom, the flowers will be smaller and less full.

Does Common St. John's wort need special care about sunlight during its different growth stages?

Common St. John's wort is great flowers in gardens and will have optimum blooming if it gets six hours of sunlight a day minimum. Sometimes, flowers stay fresh longer if they're partially shaded during the really hot parts of the day. When Common St. John's wort is young, gardeners want to ensure their younger plants are getting plenty of sunlight but don't have to endure intense heat during the afternoon sunlight. If you have a fully mature plant, provide it with plenty of sun so it may keep up its growth properly.

How much light does Common St. John's wort need for photosynthesis?

Common St. John's wort will need a minimum of six hours of light to best support their photosynthesis cycles. These flowering plants need the sun to help their foliage and blooms grow. However, certain perennial flowering plants like the Giant Coreopsis might need anywhere from eight to twelve hours of full sun a day to maintain their large flowers and healthy foliage.

How much light should Common St. John's wort get per day to grow healthily?

If you want your Common St. John's wort to grow healthy and bloom as much as possible during its blooming season, you should try to give your plant six hours of direct sunlight. Some perennial plants might even do more sunlight and could sit in the sun for up to twelve hours, depending on the heat in the area and the general environment. Plants like the Red Hot Poker and Giant Coreopsis thrive in much hotter climates and might sit in all types of strong sunlight.

Some home gardeners have to use grow lights because their spaces don't allow for tons of outdoor sunlight. Most perennials could grow happily in grow lights, but they will need anywhere from eight to fourteen hours of artificial light to stay strong since these lights don't have as much power as the sun.

Pruning

Common St. John's wort doesn't need much pruning. To promote more lush growth, trim 1/5-1/4 of the total branch length by the end of spring or early summer, which promotes new branches to sprout. Common St. John's wort buds and leaves both grow in pairs. Generally speaking, cutting one branch off promotes the pair of buds beneath the incision to develop into two branches.

For common St. John's wort with robust growth and branches crossing inward, winter is the time for an overall pruning. As perennial herbaceous plants, you may just clip them flat with a sickle and they will revive. Common St. John's wort has a short life span, so you can also consider getting new seedlings to replace the old ones once they start to decline.

When should I prune my Common St. John's wort?

You can prune your Common St. John's wort any time you notice dead, diseased, or damaged leaves during the growing season. Once you notice such a leave, locate an unwanted leaf, then follow its stem all the way to the bottom of petiole. Removing dead stems will increase the light and ventilation of the plant and help it to grow. You can cut its stem just above the soil’s surface to remove it. Such pruning can take place as needed during spring and summer. Also, this plant can bloom any time between spring and fall, and some gardeners choose to remove flower buds before they have a chance to open. Removing unopened flower buds allows this plant to focus most of its growing energy on its beautiful leaves. However, pruning in this manner does not necessarily influence the plant’s overall health. Cutting back should be done late in the winter to early spring. Ideally, you should wait until you see new basal growth before you cut off the dead and dried winter parts, to about 6 inches from the ground.

How can I prune my Common St. John's wort?

Pruning the Common St. John's wort is as easy as waiting until you notice dead or damaged leaves on your plant. When you recognize these leaves, equip yourself with a pair of sharp and sterile hand pruning shears. Hand pruning shears will work best as larger tools like loppers will not be well suited to the precise cuts you need to make. Once you have a proper set of pruning tools, locate an unwanted leaf, then follow its stem all the way to the bottom of petiole. Removing dead stems will increase the light and ventilation of the plant and help it to grow. Cut the stem just above where it exits the soil to remove it entirely. If you wish to stop this plant from flowering, you can use the same pruning shears to remove any buds before they open. Finally, you may prefer to just trim off dead or damaged portions of the plant, including deadheading spent flowers, to keep it looking its best. This can be done at any time of year. Diseased or damaged stems should be cut right at the soil line and removed completely. Blooms should be cut off just below the flower head. Cutting back should be done late in the winter to early spring. Ideally, you should wait until you see new basal growth before you cut off the dead and dried winter parts to about 6 inches from the ground.

What should I do after pruning my Common St. John's wort?

All that is required of you once you have pruned your Common St. John's wort is to clean up. Once you have pruned, deadheaded, or cut back your Common St. John's wort, gather the bits you have cut off and discard them. If there are any diseased parts of the plant that you have pruned away, do not discard them with the rest of the pruned pieces. Diseased foliage should be disposed of. When watering after pruning, be careful not to touch the wound to prevent fungus from infecting the plant through the fresh wound. Placing Common St. John's wort in a well-ventilated location will also help the wound to dry out and heal in time.

Are there any tips for pruning my Common St. John's wort?

For your major pruning, use sharp pruning sheers that will make clean cuts to avoid damaging your plants. As you are pruning your Common St. John's wort, step back occasionally to check the appearance of the plant to make sure it has the shape you want and that you are pruning it symmetricaly. It is recommended that gloves and safety glasses be worn while pruning Common St. John's wort.

Are there any instructions for pruning my Common St. John's wort?

Pruning is an important part of plant care and maintenance. Different plants have different pruning requirements. Some plants may need little to no pruning, while others may require more specific attention. Most plants should be pruned to remove damaged or unhealthy foliage. Other plants may be pruned to control their shape and size. Pruning may even be done to remove the flower heads of plants and stop them from self-seeding. Although some gardeners may find pruning a tedious task, it is a necessary evil and is an essential part of keeping your plants happy and healthy.

Advanced Care Guide

Temperature

plants of the Hypericum genus are widely distributed. They like warm, moist environments; the best temperature range for the plants is 20 to 26 ℃, but they can tolerate temperatures as low as -10 ℃. They require little water and endures drought, but don't tolerate waterlogged soil. Avoid watering so frequently that the soil gets waterlogged.

What is the optimal temperature for Common St. John's wort?

The best temperature for Common St. John's wort depends on the time of year. There are two primary seasons to discuss for temperature: the growing season, and the dormancy season. During the growing season, once Common St. John's wort has begun to sprout, the ideal temperature range should be anywhere from 65~80℉(18~27℃). Any colder than 15℉(-10℃), and the plant will suffer; its leaves may brown and wilt, but if this is a short cold snap, then Common St. John's wort may be able to survive with some help.

During the warmer parts of the year, Common St. John's wort will need to be similarly protected from temperatures that are too high. 95-105℉ (35-40℃) is the top of this plant’s temperature range, and anything above that will compromise the integrity of the foliage and blooms of Common St. John's wort. Hotter temperatures can cause wilting, drooping, and even sunburn on the leaves, which can be difficult for Common St. John's wort to recover from. There are quite a few ways to combat this issue that are quick and easy!

Temperature requirements for first year or seedling Common St. John's wort

If this is the first year of your Common St. John's wort outside as a new plant, then it may need a little extra tending during the coldest months of the year. Not only can frost more severely damage a first-year Common St. John's wort, but it can also prevent it from growing back as a healthy plant come spring. This plant needs to be kept at 40℉(5℃) or above when they’re not yet established, which can be done either by bringing your Common St. John's wort inside for a month or two, or putting up mulch or fabric barriers that protect from frost damage.

It’s also a good idea to plant Common St. John's wort in a shadier spot during the first year or two, as smaller and weaker plants have a more difficult time maintaining their own temperatures in the heat. First-year Common St. John's wort should receive no more than five hours of direct sunlight per day, particularly if the ambient daytime temperature gets above 80℉(27℃). Shadecloth and frequent watering or misting are the keys to summer heat control.

How can I protect Common St. John's wort from extreme temperatures?

If cold temperatures (below 15℉(-10℃)) do occur during the growing season, there are a few measures you can take to help protect Common St. John's wort from frost or cold damage. If you’re growing Common St. John's wort in a container, then the container can simply be brought inside in bright, indirect light until the temperatures rise up over the lower threshold again. Another option that’s better suited for ground-planted Common St. John's wort is to use mulch or horticultural fabric to create an insulated barrier around the plant, which will protect the plant from frost and cold wind.

For temperatures that are hotter than 80℉(27℃) in the shade during the day, be careful to only expose Common St. John's wort to six hours or less of sunlight per day, preferably in the morning hours. Putting up shade cloth, or a fine plastic mesh, can help reduce the amount of direct sunlight that hits the plant during the hottest parts of the day. You can also install a misting system that allows for a slow release of cooling mist around the base of the plant during the day to lower ground temperatures.

Dormant season temperature recommendations for Common St. John's wort

During the cold winter months, Common St. John's wort needs a certain measure of cold in order to stay in dormancy until it’s time to sprout. Sprouting too early, that is before the danger of the last frost has passed, can be fatal to Common St. John's wort, especially if it’s already had a head start when the frost hits. Winter temperatures should ideally stay below 32℉(0℃), but if they get up to 40℉(5℃), everything will be just fine.

An unexpected warm spell during the cold months, which can happen in more temperate climates like woodland rainforests, can trigger a premature sprout from Common St. John's wort. In this case, if there’s still imminent danger of frost, you may want to try covering it with clear plastic on stakes so that the cold has less of a chance of damaging the new sprout. This setup can be removed when the danger of frost has passed. Occasionally, Common St. John's wort will be able to resprout at the correct time without any help, but this method increases the chances of a successful second sprouting.

Soil

Common St. John's wort can adapt to a wide range of soil types. It grows well in most common soils (except for heavy clay) and prefers sandy loam with good drainage. A slightly acidic loam with a 5.5-7.0 pH value is ideal. Common St. John's wort is tolerant of barren soil and drought, but if the soil can't drain water well, waterlogging can cause the roots to rot.

Propagation

Planting

Common St. John's wort can be propagated by seeding, cuttage, or plant division. To sow seeds yourself, sow them in a sand bed. Dust a thin layer of soil on them, water once, and sprout the seeds in temperatures of 10 to 12 ℃. Keep the potting soil moist. Transplant seedlings when they grow to 5 to 10 cm tall.

For St. John's worts with dense branches, propagation is usually performed at the end of summer by soft-branch cuttage. Choose some robust, soft branches that sprouted in the current year. Cut 10 to 15 cm-long from the tip, making sure to keep at least 2 full leaves on each branch. Insert the cut branches into the soil and keep half the length aboveground. Keep the soil and the environment moist. When the seedlings reach 20 cm tall, transplant to pots. Seedlings need to grow to 70 cm tall to move outdoors or wait until the end of the next summer.

plant common St. John's wort in the early spring or early fall. Choose a cool, shaded place, such as within tree shade. Remember to clear the soil first and remove weeds. Dig a planting pit slightly shorter than the diameter of the root ball and 3 times wider. If you're planting more than one sapling, avoid planting them too close, or low light and poor ventilation may result in powdery mildew. Pile some soil around the root collar (the juncture of trunk and roots) to form a gentle slope, and this helps disperse water. After planting, press the soil firmly and water thoroughly. Note the distance between each

Some plants in the Hypericum genus have subterraneous rhizomes that tend to expand in all directions. To prevent excessive expansion, it's a good idea to fence the planting spots or set brick perimeters around them to control their growth.

Seasonal Care Tips

Seasonal Precautions

Common St. John's wort begins to flower at the end of spring. You can extend its flowering by giving it some shade. Especially potted it needs as much sunlight during the day as possible in spring and fall.

When common St. John's wort is planted without a brick perimeter or fence, remove overly lush-growing parts before the frost every fall to prevent it from growing too fast and expanding too wide. Eradicating this hardy plant requires multiple applications of 2,4-D herbicides.

Spring

Summer

Fall

Winter

This plant requires some care in the spring.

Every few years, divide large plants at the roots.

Spring is also the time to sow seeds. Choose a sunny location and cover the seeds with about one inch of soil and water thoroughly.

When new growth begins emerging, an application of all-purpose, balanced fertilizer will provide the necessary nutrients.

Don’t forget to water when the top layer of soil begins drying out.

Ensure the plant is receiving plenty of sunlight during the day.

The leaves on the plant do not thrive in bright sunshine in the summer.

Keep container plants in a shaded area.

Check the soil moisture level and increase watering frequency when rainfall is scarce. The soil may need checking daily to ensure it is not drying out.

Keep an eye out for slugs, and other garden pests, especially if there is mulch around the plant.

Cut back any spent flowers and remove any plant debris from the area.

Continue regular fertilizing to help support fall flowering.

Continue watering and fertilizing your plant as long as it grows during the early fall season.

Once the plants have entered a dormant stage, you can prune them back down to the ground; then, reduce watering.

Use a balanced, all-purpose fertilizer regularly until the colder weather causes the plant to go dormant, then stop fertilizing.

Ensure the plant still has plenty of sun during this time, placing them in locations that have full or partial sunlight.

At the end of fall, after a hard frost, you can sow the seeds for your plant to propagate more plants.

As this plant goes dormant in cold weather, there’s not much care required for this plant. It's best to provide them with cold protection, however.

After cutting back the stems, you can cover the beds with tarp or mulch to add a barrier against the chill winter winds and frost.

Only water indoor or warmer-climate plants once the soil becomes dry to the touch, but for the most part you should leave this plant to itself during this season after providing it some shelter from the cold.

Common Pests & Diseases

Common issues for Common St. John's wort based on 10 million real cases

Brown spot

This infection can cause brown spots or patches to appear on the plant.

Solutions: In minor cases of brown spot, there isn’t any need to treat the disease. However, if much of the foliage is affected and defoliation occurs, the plant will benefit from getting rid of the infection. It is recommended to start by applying organic treatment options, working up to the more potent synthetic, chemical fungicides if necessary. Organic options won’t kill the fungus, but will prevent it from spreading. Dissolve ½ teaspoon of baking soda and one teaspoon of liquid soap in a gallon of water. Using a spray bottle, spray on tops and bottoms of leaves until the mixture drips off. Repeat every two weeks until existing spots stop enlarging and new spots no longer appear. Spray a copper-based fungicidal soap on the leaves, coating the top and bottom leaf surfaces. Reapply as directed on the product label. Copper penetrates the leaf surface and prevents germination of spores so the fungus cannot spread. Apply an all-purpose fungicide to the entire plant, following the label instructions carefully.

Flower withering

Flowers may dry out due to a sudden change in environment or because the plant has completed its normal flowering period.

Solutions: If flower withering is a natural progression due to age, there is nothing that can be done to slow or stop the process. Once hormones within the plant begin the process of senescence, it’s irreversible. For lack of water, immediately water the plant using room temperature rainwater, bottled spring water, or filtered tap water. Water container plants until excess water drains out the bottom; water in-ground plants until the soil is soaked but there isn’t standing water on the surface. In the event of nutritional deficiencies, the best solution is to use a granular or water-soluble liquid fertilizer, and apply it to the soil at about half the recommended dosage. Keep it off the leaves and make sure granular products are watered into the soil well. If the plant is infected with a bacterial or fungal pathogen, there is no course of treatment that cures the diseased plants. The best solution is to remove the infected plants and dispose of the plant material off-site. Do not put in a compost pile.

Leaf beetles

Leaf beetles are a class of colored insects 1 to 2 cm in size. They gnaw on leaves and petals resulting in small, round holes scattered over the surface.

Solutions: For less serious cases: Remove beetles, nymphs, and eggs. Remove all life stages of the beetles and kill them by placing them in a bucket of warm, soapy water. This can be done more easily by placing the bucket under affected leaves and shaking the plant. This method is most effective in the afternoon when leaf beetles are more active. Always dispose of insects in a sealed bag or container to avoid escape and spread. To treat more serious infestations: Apply organic insecticides. Use naturally-derived insecticides before moving on to synthetic insecticides. Neem oil and pyrethrum are naturally-derived insecticides that should be applied following label instructions. Apply synthetic insecticides. Examples of insecticides effective for leaf beetles include carbaryl, permethrin, and bifenthrin. Apply insecticides according to label instructions.

Leaf scorch

Leaf blight causes leaves to dry out and turn brown starting at their tips.

Solutions: The solution to leaf scorch will depend on the cause, however, in general all cultural care methods that improve plant health and root functionality will reduce symptoms. Mulching the root zone (preferably with wood chip mulch) helps retain moisture, reduce evaporation, and promotes a healthy, functional root environment that is critical for water movement to the leaves. Check the root collar for girdling or circling roots that strangle the trunk and limit water and nutrient movement. Protect trees from severe root damage of nearby construction and excavation. If fertilizer burn is to blame, irrigate the soil deeply to flush out excess fertilizer salts. However, keep in mind that fertilizer runoff is an environmental pollutant. Avoiding excess fertilization in the first place is the best approach. If soil testing has revealed a potassium deficiency, apply a potassium fertilizer and water well. Even if you have enough potassium in the soil, plants will not be able to take it up if the soil is consistently too dry. Severely affected twigs may be removed using a pair of sharp and sanitized pruning shears, as weakened branches are susceptible to secondary infections. If your plant has bacterial leaf scorch, there is no cure. Antibiotic injections applied by a professional can reduce symptoms for a season, however, the above cultural management methods are the best options to reduce symptoms and prolong life. An infected plant will likely die within ten years.

Aged yellow and dry

Natural aging can cause leaves to turn yellow and dry out.

Solutions: If the yellowing and drying of leaves and flowers is a natural progression due to age, nothing can be done to slow or stop the process. Once hormones within the plant begin the process of senescence, it’s irreversible.

Underwatering

Leaves may wilt for a variety of reasons.

Solutions: The easiest (and most obvious) way to address underwatering is to fully hydrate the plant. However, this must be done carefully. A common mistake that many gardeners make is to douse their underwatered plants with water. This can overwhelm the roots of the plant and shock its system, something that can be even more damaging than the lack of water to begin with. Instead, water thoroughly and slowly, taking breaks to let the water slowly saturate through the soil to get to the roots. Use room temperature water, as cold water might be too much of a shock. In the future, shorten the time between waterings. A good rule of thumb is to check the soil around each plant daily. If it’s dry to at least two inches down, it’s time to water. If a container plant is repeatedly drying out very quickly, repotting into a slower-draining container might be a good idea, too.

Treat and prevent plant diseases.

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Toxicity

Highly Toxic to Humans

Common St. John's wort can potentially cause adverse reactions in humans with an allergy to the plant or who are taking prescription drugs that may react with it. The leaves and flowers of the plant, or products containing them, can cause adverse reactions from both external and internal uses. Symptoms of an allergic reaction may include mild to moderate symptoms such as nausea, stomach pain, decreased appetite, diarrhea, dizziness, fatigue, headache, dry mouth, confusion, sedation, photosensitivity, and restlessness. Common St. John's wort can cause severe or life-threatening side effects when combined with prescription drugs, especially antipsychotics, antidepressants, anticoagulants, and contraceptives.

Toxic to Dogs

Common St. John's wort is mildly toxic to dogs. Physical exposure to any above-ground part of the plant may cause contact dermatitis, with more severe cases resulting in skin ulcers or blisters. Ingestion may lead to fever, gastrointestinal distress, and photosensitivity (which causes an aversion to strong lights - in extreme cases, temporary blindness may occur). Luckily, most cases of common St. John's wort poisoning are mild and resolve themselves after several days.

Toxic to Cats

The flesh of the common St. John's wort plant (Hypericum perforatum) is considered dangerous to cats as it can alter hormonal balance and cause them to behave erratically. Do not delay getting a cat treated at a veterinary hospital after even a small amount is consumed, as even chewing on the leaves can cause adverse effects.

More About Common St. John's Wort

Plant Type

Herb

Lifespan

Perennial

Spread

30 to 61 cm

Bloom Time

Mid spring, Late spring, Summer

Flower Color

Yellow

Gold

Leaf Color

Green

Flower Size

2 to 3.5 cm

Plant Height

30 to 100 cm

Name story

Common St. John's wort

Common St. John's wort is named as such because of its blossoms and it is harvested during the summer solstice in late June, around St John's Feast Day on 24 June. The herb would be hung on house and stall doors on St John's Feast day with the belief that it wards off evil spirits to safeguard against harm and sickness to man and livestock.

Usages

Garden Use

Common St. John's wort is an attractive garden ornamental with ornate, star-shaped flowers. It is often viewed as a weedy plant, but is grown in prairie and meadow landscapes where it is useful in attracting pollinators. Common St. John's wort is also grown in herb gardens, wildlife gardens, as borders and woodland margins.

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Common Problems

Why do leaves of my common St. John's wort turn yellow?

Yellowing leaves result from many causes, including nitrogen or iron deficiencies, insufficient light, waterlogged soil (the roots of plants need oxygen to grow), or dehydrated soil. If new leaves are yellow with green veins, it usually indicates an iron deficiency. If older leaves turn yellow while the new leaves are still green, it usually means a lack of nitrogen.

Nitrogen deficiency is more common than iron deficiency, but both can be solved using appropriate fertilizer. Keep the soil properly moist, but free of standing water. If leaves turn yellow right after a transplant but the newly-grown leaves are green, it may be due to the plant's dormancy.

Why doesn't my common St. John's wort bloom?

There are many reasons for this phenomenon:

It might be because of insufficient light. Common St. John's wort can grow in shaded, cool places, but it blooms more abundantly with ample sunlight.
Inappropriate fertilizing. Fertilizers with high nitrogen content can cause excessive growth of branches and leaves and a lack of blooms.
Pruning at the wrong time can also cause failure to bloom.
It may be that your specific variety doesn't adapt well to where you planted it.
It may also be too early for it to flower. Wait a bit longer and see.

Caring for a New Plant

The following pictures and instructions for herb are aimed to help your plants adapt and thrive in a new environment.

Picking a Healthy Herb

Check Its Health

Whole Plant

Symmetrical crown, evenly distributed branches, full and compact shape, no excessive growth, close internodes, and uniform leaf size.

Leaves

Check the inside of the plant, shaded and overlapping areas, back of leaves. Even colour, no yellowing, no brown spots, no crawling insects, no cobwebs, no deformities, no wilting.

Stems

No mold, browning or soft rot at the base of the plant.

Health Troubleshooting

Whole Plant

1 Asymmetrical crown or missing, uneven branching: prune the weak and slender branches of the larger portion of the asymmetrical crown.

2 Internodes are longer in the upper part, leaves are sparse and smaller on top: increase light intensity or duration.

Stems

Mildew, browning, or soft rot at the base: place the plant in a ventilated, dry environment and water with fungicide.

Leaves

1 Uneven leaf color and yellowing: prune yellow leaves and check if there are signs of rot at the base of the plant. Spray with fungicide for severe cases.

2 Brown spots or small yellow spots: place the plant in a ventilated area and avoid watering the leaves. Spray with fungicide for severe cases.

3 Tiny crawling insects on the back of leaves or spider webs between leaves: increase light exposure and spray with insecticide for severe cases.

4 Deformations or missing parts on leaves: determine if it's physical damage or pest infestation. Linear or tearing damage is physical, while the rest are pests. Spray with insecticide.

5 Wilting leaves: provide partial shade and avoid excessive sun exposure. Remove 1/3 to 1/2 of the leaves for severe cases.

Treat and prevent plant diseases.

AI-powered plant doctor helps you diagnose plant problems in seconds.

Check Its Growing Conditions

Soil Check

Soil should smell fresh like after a rain and no musty odor.

Light Check

Check the light requirement of the plant and if it match with planting location.

Temperature Check

Check if the current outdoor temperature is too low or too high.

Condition Troubleshooting

Soil

Chalky, Loam

Soil smells musty or foul: check the root system for decay, place the plant in a ventilated, dry environment, and water with fungicide.

Ideal Temperature

-10 to 35 ℃

Outdoor temperature is not suitable for the plant: wait until it's a more favorable temperature for growth.

Suitable Light

Full sun, Partial sun

Insufficient light: Herbaceous plants need good light to bloom. If it doesn't have enough light, it may not bloom or have fewer blooms. Consider moving the plant to a sunnier spot or switching to a different plant that thrives in your light conditions.

Transplant recovery: After 3 days without major wilting, increase the light gradually over the course of a week. If the plant starts losing leaves or drooping, keep it in the shade. Continue shading until the plant has recovered. If it's yellowing and losing many leaves, the light is too low, so increase it.

Adapting Your New Herb

Step 1

Repotting

Plant your plant promptly in its final location or in a new pot, if conditions are suitable. When transplanting, clean the roots of the plant and keep the root system intact. Prune any blackened or rotten roots, spread out a heavily tangled root system, and mix in some well-rotted organic fertilizer. Use permeable soil and water thoroughly after planting.

Step 2

Pruning

Not usually needed. Cut off yellow or diseased leaves and crowded leaves that appear wilted or falling.

Step 3

Watering

Increase watering in the first week to keep soil moist. Water when soil is slightly dry, for at least 2 weeks. Avoid over-watering. Do not water when there is water on your fingers after touching the soil.

Step 4

Fertilizing

Add a small amount of base fertilizer during transplanting or repotting. No other fertilizer needed for the first month.

Know the light your plants really get.

Find the best spots for them to optimize their health, simply using your phone.

Common St. John's Wort

Repotting

Plant promptly in final location or new pot. Clean roots, use organic fertilizer, permeable soil, and water thoroughly.

Pruning

Cut off yellow or diseased leaves and crowded leaves that appear wilted or falling.

Watering

Water new plants more often for 2 weeks. Avoid over/under watering by checking the soil.

Fertilizing

Add base fertilizer during transplanting. No other fertilizer is needed for the first month.

Sunlight

Regular sun exposure for indoor plants. Shade after transplanting/repotting, then gradually increase light if there is no wilting. Increase light if yellowing and leaf drop occur.

Save and print our adaptation tips card for quick and easy reference.

Download

Common St. John's Wort

Repotting

Plant promptly in final location or new pot. Clean roots, use organic fertilizer, permeable soil, and water thoroughly.

Pruning

Cut off yellow or diseased leaves and crowded leaves that appear wilted or falling.

Watering

Water new plants more often for 2 weeks. Avoid over/under watering by checking the soil.

Fertilizing

Add base fertilizer during transplanting. No other fertilizer is needed for the first month.

Sunlight

Regular sun exposure for indoor plants. Shade after transplanting/repotting, then gradually increase light if there is no wilting. Increase light if yellowing and leaf drop occur.

Plants with Same Care Needs

Poison ivy

In pop culture, poison ivy is a symbol of an obnoxious weed because, despite its unthreatening looks, it gives a highly unpleasant contact rash to the unfortunate person who touches it. Still, it is commonly eaten by many animals, and the seeds are a favorite with birds. The leaves turn bright red in fall. Its sister species, Western poison ivy (Toxicodendron rydbergii), is not considered to be invasive in the United States, but is noxious in Australia and New Zealand.

Bloom Time

Mid spring

Garden phlox

The garden phlox is a flowering plant that is native to the United States. The name, phlox, comes from the Latin for "flame," reflecting its bright colors. Garden phlox flowers can become important food sources for insects and hummingbirds.

Bloom Time

Mid spring

Ground ivy

Ground ivy (Glechoma hederacea) is a perennial evergreen trailing plant, often found in grasslands and woodlands. Saxon peoples once spread the plant, but it has become invasive in some parts of the world now. The fast-growing ground ivy can be toxic to horses but generally cannot harm other animals or humans.

Bloom Time

Mid spring

Persian silk tree

Albizia julibrissin, colloquially known as persian silk tree, is a deciduous plant with characteristic pink, fuzzy inflorescences. Persian silk tree is mainly cultivated for decorative purposes. Its flowers have a mild, sweet smell and are often visited by butterflies, bees and hummingbirds.

Bloom Time

Mid spring

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How to Care for Common St. John's Wort

Symbolism

Animosity, superstition

Water

Every week

Sunlight

Full sun

Basic Care Guide

Water

Potted Common St. John's wort

Ground Common St. John's wort

Overwater and underwater

Never miss a care task again!

Plant care made easier than ever with our tailor-made smart care reminder.

What is the best way to water my Common St. John's wort?

What should I do if I water my Common St. John's wort too much or too little?

How often should I water my Common St. John's wort?

How much water does my Common St. John's wort need?

How should I water my Common St. John's wort at different growth stages?

How should I water my Common St. John's wort through the seasons?

What's the difference between watering my Common St. John's wort indoors and outdoors?

Fertilizer

Why do I need to fertilize my Common St. John's wort?

When is the best time to fertilize my Common St. John's wort?

When should I avoid fertilizing my Common St. John's wort?

What type of fertilizer does my Common St. John's wort need?

How do I fertilize my Common St. John's wort?

What happens if I fertilize my Common St. John's wort too much?

Sunlight

Know the light your plants really get.

Find the best spots for them to optimize their health, simply using your phone.

What type of sunlight does Common St. John's wort need?

Can sunlight damage Common St. John's wort? How to protect Common St. John's wort from the sun and heat damage?

Should I protect Common St. John's wort from sun exposure?

What will happen if Common St. John's wort gets inadequate sunlight?

Does Common St. John's wort need special care about sunlight during its different growth stages?

How much light does Common St. John's wort need for photosynthesis?

How much light should Common St. John's wort get per day to grow healthily?

Pruning

When should I prune my Common St. John's wort?

How can I prune my Common St. John's wort?

What should I do after pruning my Common St. John's wort?

Are there any tips for pruning my Common St. John's wort?

Are there any instructions for pruning my Common St. John's wort?

Advanced Care Guide

Temperature

What is the optimal temperature for Common St. John's wort?

Temperature requirements for first year or seedling Common St. John's wort

How can I protect Common St. John's wort from extreme temperatures?

Dormant season temperature recommendations for Common St. John's wort

Soil

Propagation

Planting

Seasonal Care Tips

Seasonal Precautions

Spring

Summer

Fall

Winter

This plant requires some care in the spring.

Every few years, divide large plants at the roots.

Spring is also the time to sow seeds. Choose a sunny location and cover the seeds with about one inch of soil and water thoroughly.

When new growth begins emerging, an application of all-purpose, balanced fertilizer will provide the necessary nutrients.

Don’t forget to water when the top layer of soil begins drying out.

Ensure the plant is receiving plenty of sunlight during the day.

The leaves on the plant do not thrive in bright sunshine in the summer.

Keep container plants in a shaded area.

Check the soil moisture level and increase watering frequency when rainfall is scarce. The soil may need checking daily to ensure it is not drying out.

Keep an eye out for slugs, and other garden pests, especially if there is mulch around the plant.

Cut back any spent flowers and remove any plant debris from the area.

Continue regular fertilizing to help support fall flowering.

Continue watering and fertilizing your plant as long as it grows during the early fall season.

Once the plants have entered a dormant stage, you can prune them back down to the ground; then, reduce watering.

Use a balanced, all-purpose fertilizer regularly until the colder weather causes the plant to go dormant, then stop fertilizing.

Ensure the plant still has plenty of sun during this time, placing them in locations that have full or partial sunlight.

At the end of fall, after a hard frost, you can sow the seeds for your plant to propagate more plants.

As this plant goes dormant in cold weather, there’s not much care required for this plant. It's best to provide them with cold protection, however.

After cutting back the stems, you can cover the beds with tarp or mulch to add a barrier against the chill winter winds and frost.

Common Pests & Diseases

Common issues for Common St. John's wort based on 10 million real cases

Brown spot

This infection can cause brown spots or patches to appear on the plant.

Learn More

Flower withering

Flowers may dry out due to a sudden change in environment or because the plant has completed its normal flowering period.

Learn More

Leaf beetles

Leaf beetles are a class of colored insects 1 to 2 cm in size. They gnaw on leaves and petals resulting in small, round holes scattered over the surface.

Learn More

Leaf scorch

Leaf blight causes leaves to dry out and turn brown starting at their tips.

Learn More

Aged yellow and dry

Natural aging can cause leaves to turn yellow and dry out.

Learn More

Underwatering

Leaves may wilt for a variety of reasons.

Learn More

Treat and prevent plant diseases.

AI-powered plant doctor helps you diagnose plant problems in seconds.

Toxicity

Highly Toxic to Humans

Toxic to Dogs

Toxic to Cats

* The judgment on toxicity and danger is for reference only. We DO NOT GUARANTEE any accuracy of such judgment. Therefore, you SHALL NOT rely on such judgment. It is IMPORTANT TO SEEK PROFESSIONAL ADVICE in advance when necessary.

More About Common St. John's Wort

Plant Type

Herb

Lifespan

Perennial

Spread

30 to 61 cm

Bloom Time

Mid spring, Late spring, Summer

Flower Color

Yellow

Gold

Leaf Color

Green

Flower Size

2 to 3.5 cm

Plant Height

30 to 100 cm

Name story

Common St. John's wort

Usages

Garden Use

View More Info

Find your perfect green friends.

Plan your green oasis based on your criteria: plant type, pet safety, skill level, sites, and more.

Common Problems

Why do leaves of my common St. John's wort turn yellow?

Why doesn't my common St. John's wort bloom?

There are many reasons for this phenomenon:

It might be because of insufficient light. Common St. John's wort can grow in shaded, cool places, but it blooms more abundantly with ample sunlight.
Inappropriate fertilizing. Fertilizers with high nitrogen content can cause excessive growth of branches and leaves and a lack of blooms.
Pruning at the wrong time can also cause failure to bloom.
It may be that your specific variety doesn't adapt well to where you planted it.
It may also be too early for it to flower. Wait a bit longer and see.

Caring for a New Plant

The following pictures and instructions for herb are aimed to help your plants adapt and thrive in a new environment.

Picking a Healthy Herb

Check Its Health

Whole Plant

Symmetrical crown, evenly distributed branches, full and compact shape, no excessive growth, close internodes, and uniform leaf size.

Leaves

Check the inside of the plant, shaded and overlapping areas, back of leaves. Even colour, no yellowing, no brown spots, no crawling insects, no cobwebs, no deformities, no wilting.

Stems

No mold, browning or soft rot at the base of the plant.

Health Troubleshooting

Whole Plant

Stems

Leaves

1 Asymmetrical crown or missing, uneven branching: prune the weak and slender branches of the larger portion of the asymmetrical crown.

2 Internodes are longer in the upper part, leaves are sparse and smaller on top: increase light intensity or duration.

Mildew, browning, or soft rot at the base: place the plant in a ventilated, dry environment and water with fungicide.

1 Uneven leaf color and yellowing: prune yellow leaves and check if there are signs of rot at the base of the plant. Spray with fungicide for severe cases.

2 Brown spots or small yellow spots: place the plant in a ventilated area and avoid watering the leaves. Spray with fungicide for severe cases.

3 Tiny crawling insects on the back of leaves or spider webs between leaves: increase light exposure and spray with insecticide for severe cases.

4 Deformations or missing parts on leaves: determine if it's physical damage or pest infestation. Linear or tearing damage is physical, while the rest are pests. Spray with insecticide.

5 Wilting leaves: provide partial shade and avoid excessive sun exposure. Remove 1/3 to 1/2 of the leaves for severe cases.

Treat and prevent plant diseases.

AI-powered plant doctor helps you diagnose plant problems in seconds.

Check Its Growing Conditions

Soil Check

Soil should smell fresh like after a rain and no musty odor.

Light Check

Check the light requirement of the plant and if it match with planting location.

Temperature Check

Check if the current outdoor temperature is too low or too high.

Condition Troubleshooting

Soil

Ideal Temperature

Suitable Light

Chalky, Loam

Soil

Soil smells musty or foul: check the root system for decay, place the plant in a ventilated, dry environment, and water with fungicide.

-10 to 35 ℃

Ideal Temperature

Outdoor temperature is not suitable for the plant: wait until it's a more favorable temperature for growth.

Full sun, Partial sun

Suitable Light

Adapting Your New Herb

Step 1

Repotting

Step 2

Pruning

Not usually needed. Cut off yellow or diseased leaves and crowded leaves that appear wilted or falling.

Step 3

Watering

Step 4

Fertilizing

Add a small amount of base fertilizer during transplanting or repotting. No other fertilizer needed for the first month.

Know the light your plants really get.

Find the best spots for them to optimize their health, simply using your phone.

Plants with Same Care Needs

Poison ivy

Toxicodendron radicans

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How to Care for Common St. John's Wort

Symbolism

Basic Care Guide

Water

Water

Never miss a care task again!

Fertilizer

Fertilizer

Sunlight

Know the light your plants really get.

Pruning

Advanced Care Guide

Temperature

Soil

Propagation

Planting

Propagation

Seasonal Care Tips

Seasonal Precautions

Spring

Summer

Fall

Winter

This plant requires some care in the spring.

The leaves on the plant do not thrive in bright sunshine in the summer.

Continue watering and fertilizing your plant as long as it grows during the early fall season.

As this plant goes dormant in cold weather, there’s not much care required for this plant. It's best to provide them with cold protection, however.

Common Pests & Diseases

Treat and prevent plant diseases.

Toxicity

Aloe

Philodendron

Peace Lily

Snake Plant

Daffodil

Hydrangea

Rhododendrons

Rhubarb

Bittersweet Nightshade

Buttercups

Foxgloves

How to Tend to Poisonous Plants

How to Get Rid of Poisonous Plants

Aloe

Philodendron

Peace Lily

Snake Plant

Daffodil

Hydrangea

Rhododendrons

Rhubarb

Bittersweet Nightshade

Buttercups

Foxgloves

How to Tend to Poisonous Plants

How to Get Rid of Poisonous Plants

More About Common St. John's Wort

Name story

Usages

Find your perfect green friends.

Common Problems

Why do leaves of my common St. John's wort turn yellow?

Why doesn't my common St. John's wort bloom?

Caring for a New Plant

Check Its Health

Health Troubleshooting

Treat and prevent plant diseases.

Check Its Growing Conditions

Condition Troubleshooting

Know the light your plants really get.

Plants with Same Care Needs

Botanist in your pocket

App

How to Care for Common St. John's Wort

Symbolism

Basic Care Guide

Water

Water

Never miss a care task again!

Fertilizer