Sulfur cosmos (Cosmos sulphureus) Flower, Leaf, Care, Uses

Sulfur cosmos is a tough customer that is well-adapted to dry conditions. It must never be over-watered since this will damage the plant. When it is young, keep the surrounding soil moist. When fully grown assume that the plant doesn't need supplemental watering at all, except in drought conditions when a weekly watering should suffice.

Fertilization

A basic rule with sulfur cosmos is to not use fertilizer at all. This plant is adapted to thrive even in poor soils, so it should not need supplementary fertilization. However, if the plant is looking unhealthy, then it is a good idea to use an all-purpose fertilizer, applying it once a year at the start of the spring growing season.

Soil

Sand, Loam, Chalky, Clay, Acidic, Neutral, Alkaline

Potting Suggestions

Yellow cosmos can be transplanted to pots when seedlings grow to 6 to 8 cm.

Sunlight

Full sun, Partial sun

Know the light your plants really get.

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

Download the App

A Botanist in Your Pocket

Scan QR code to download

Sulfur cosmos

Water

Twice per week

Sunlight

Full sun

Hardiness Zones

3 to 9

Planting Time

Late summer, Fall

Download and print this plant care card and attach it to your plants

Download

Questions About Sulfur cosmos

Watering

Pruning

Sunlight

Temperature

Fertilizing

What is the best way to water my Sulfur cosmos?

To water Sulfur cosmos, you can use a garden hose with a spray nozzle, a watering can, or just about any other common watering tool. Generally, Sulfur cosmos is not too picky about how they receive their water, as they can live off of rainwater, tap water, or filtered water. Often, you should try not to water this plant from overhead, as doing so can damage the leaves and flowers and may lead to disease as well. At times, the best method for watering this plant is to set up a drip irrigation system. These systems work well for Sulfur cosmos as they apply water evenly and directly to the soil. For one Sulfur cosmos that grows in a container, you can use a similar watering approach while changing the tools you use. To water a container-grown Sulfur cosmos, use a cup, watering can, or your tap to apply water directly to the soil.

What should I do if I water my Sulfur cosmos too much or too little?

The remedy for underwatering Sulfur cosmos is somewhat obvious. When you notice that your plant lacks moisture, simply begin watering it on a more regular basis. The issue of overwatering can be a much more dire situation, especially if you fail to notice it early. When your Sulfur cosmos is overwatered, it may contract diseases that lead to its decline and death. The best way to prevent this outcome is to choose a proper growing location, one that receives plenty of sunlight to help dry the soil and has good enough drainage to allow excess water to drain rather than pooling and causing waterlogged soils. If you overwater your Sulfur cosmos that lives in a pot, you may need to consider changing it to a new pot. Your previous container may not have contained soil with good drainage or may not have had sufficient drainage holes. As you repot your overwatered Sulfur cosmos, make sure to add loose soils and to use a pot that drains efficiently.

How often should I water my Sulfur cosmos?

Sulfur cosmos needs water regularly throughout the growing season. Beginning in spring, you should plan to water this plant about once per week. As the season presses on and grows warmer, you may need to increase your watering rate to about two to three times per week. Exceeding at this rate can be detrimental to your Sulfur cosmos. With that said, you should also ensure that the soil in which your Sulfur cosmos grows remains relatively moist but not wet, regardless of how often you must water to make that the case. Watering Sulfur cosmos that lives in a pot is a bit different. Generally, you'll need to increase your watering frequency, as the soil in a pot can heat up and dry out a bit faster than ground soil. As such, you should plan to water a container-grown Sulfur cosmos a few times per week in most cases, versus just once per week for an in-ground plant.

How much water does my Sulfur cosmos need?

There are a few different ways you can go about determining how much water to give to your Sulfur cosmos. Some gardeners choose to pick their water volume based on feeling the soil for moisture. That method suggests that you should water until you feel that the first six inches of soil have become moist. Alternatively, you can use a set measurement to determine how much to water your Sulfur cosmos. Typically, you should give your Sulfur cosmos about two gallons of water per week, depending on how hot it is and how quickly the soil becomes dry. However, following strict guidelines like that can lead to overwatering if your plant requires less than two gallons per week for whatever reason. When growing Sulfur cosmos in a container, you will need to use a different method to determine how much water to supply. Typically, you should give enough water to moisten all of the layers of soil that have become dry. To test if that is the case, you can simply stick your finger in the soil to feel for moisture. You can also water the soil until you notice a slight trickle of excess water exiting the drainage holes of your pot.

How can I tell if i'm watering my Sulfur cosmos enough?

It can be somewhat difficult to avoid overwatering your Sulfur cosmos. On the one hand, these plants have relatively deep roots that require you to moisten the soil weekly. On the other hand, Sulfur cosmos are plants that are incredibly susceptible to root rot. Along with root rot, your Sulfur cosmos may also experience browning as a result of overwatering. Underwatering is far less likely for your Sulfur cosmos as these plants can survive for a while in the absence of supplemental watering. However, if you go too long without giving this plant water, it will likely begin to wilt. You may also notice dry leaves.

How should I water my Sulfur cosmos through the seasons?

You can expect your Sulfur cosmos’s water needs to increase as the season moves on. During spring, you should water about once per week. Then, as the summer heat arrives, you will likely need to give a bit more water to your Sulfur cosmos, at times increasing to about three times per week. This is especially true of Sulfur cosmos that grow in containers, as the soil in a container is far more likely to dry out faster than ground soil when the weather is warm. In autumn, while your Sulfur cosmos is still in bloom, it may need a bit less water as the temperature has likely declined, and the sun is no longer as strong as it was in summer.

How should I water my Sulfur cosmos at different growth stages?

Sulfur cosmos will move through several different growth stages throughout the year, some of which may require more water than others. For example, you will probably start your Sulfur cosmos as a seed. While the seed germinates, you should plant to give more water than your Sulfur cosmos will need later in life, watering often enough to maintain consistent soil moisture. After a few weeks, your Sulfur cosmos will grow above the soil and may need slightly less water than at the seedling phase. Then, once this plant is mature, you can begin to use the regular watering frequency of about once per week. As flower development takes place, you may need to give slightly more water to aid the process.

What's the difference between watering Sulfur cosmos indoors and outdoors?

There are several reasons why most Sulfur cosmos grow outdoors rather than indoors. The first is that these plants typically grow to tall. The second reason is that Sulfur cosmos needs more daily sunlight than most indoor growing locations can provide. If you are able to provide a suitable indoor growing location, you may find that you need to give your Sulfur cosmos water a bit more often than you would in an outdoor growing location. Part of the reason for this is that indoor growing locations tend to be a lot drier than outdoor ones due to HVAC units. The other reason for this is that soil in containers can dry out relatively quickly as well compared to soil in the ground.

Is pruning necessary for my Sulfur cosmos?

Sulfur cosmos is a kind of annual plant so it doesn't need much pruning. You only need to cut off and clean the diseased, yellow or dropped leaves and stems during its growing period. This will help your Sulfur cosmos to stay away from pathogens infection.

How do I prune my Sulfur cosmos?

During the growth of the plant, yellowing, drying and spotted leaves are produced, and these spotted and discolored leaves need to be trimmed off. If the whole piece of leave is discolored or infected, you will need to cut it off completely. In other situations, you will only need to cut off the discolored or infected part on certain leaves. Sulfur cosmos above the ground will die and dry up in the winter, and the dead plants need to be cleaned up.

Are there any cautions I should be careful with when pruning my Sulfur cosmos?

Sulfur cosmos leaves are delicate, so take care not to score or bruise them. Unless the leaves are withered or heavily discolored, do not prune the leaves from the lowermost branches unless they’re damaged. They typically grow the largest, so they supply the plant with critical energy to keep it growing right. Please prevent the wounds from water after pruning until they are fully recovered. Remember always sterilize the tools before pruning. When the pruning is finished, please throw all the waste leaves and stems into the trashbins to avoid diseases and bugs.

Are there any tips for pruning my Sulfur cosmos?

Sterilize all the tools before pruning; unclean tools will pass pathogens to the plant through wounds;
Prune on sunny days because the new cuts will be infected by pathogens if they're distained by rain or water.
Throw all the waste leaves and stems into trashbins, they will easily rot and attract diseases and bugs

When should/shouldn't I prune my Sulfur cosmos?

Expect to prune your Sulfur cosmos every week if it’s growing well or every two weeks if it grows slowly. It is always good to prune it on sunny days because if you prune it on rainy days, the rainwater will distain the cuts and cause the whole plant to be infected.

What should I look for when pruning my Sulfur cosmos in different seasons?

Because Sulfur cosmos is an annual plant, the pruning should take place basically during the seasons that the plant grows rapidly. During the growth of the plant, yellowing, drying and spotted leaves are produced, and these spotted and discolored leaves need to be trimmed off.

How much sunlight should Sulfur cosmos get per day to grow healthily?

You must expose the plants to at least 6 to 8 hours of sunlight daily. They prefer more exposure to the morning light, especially in the summer. The Sulfur cosmos needs full sun and more sunlight that it can get. The more light these species get, the more they can manufacture food, produce beautiful blooms, and survive.

What type of sunlight does Sulfur cosmos need?

The Sulfur cosmos grows best under full sunlight. It's best not to crowd them together so they can get exposure to the sun evenly. The leaves shouldn't be starved with sunlight. If planted in pots, try to expose the herbaceous flowers in windows with direct sun and ensure they receive full sunlight regardless of the months.

They don't tend to do well in partial or filtered light as this will not produce strong stems and healthy flowers. It's best if the Sulfur cosmos is always exposed to the sun.

Can sunlight hurt plants? How to protect Sulfur cosmos from sun and heat damage?

When the temperature rises above 90℉(32℃), the Sulfur cosmos can get damaged by extreme temperatures, especially if they are exposed to many hours of sun. It's always ideal for providing some shade from the light in the afternoon in the summer. It's always important to keep in mind that the sunlight in the summer is stronger than the one in the winter. Sunlight exposure is also 50% longer in the summer than in the winter.

If the Sulfur cosmos is too stressed with sunlight, you might want to keep them fully hydrated. Water them when the top of the soil is about 2 inches dry, and move the plants indoors if it's too hot outside. This is the case if they are planted in containers.

It can be normal for the plant leaves to wilt during the day. Generally, they can recover at night. However, when you notice that the Sulfur cosmos is still drooping, this means that the plant is losing water fast, and you need to water them.

Should I protect Sulfur cosmos from sun exposure?

The Sulfur cosmos does not need any protection from the sun. In fact, they love the sun, and some species are heliotropic. Plant them in south-facing gardens whenever possible so they can be exposed from morning to afternoon. While the sun can benefit them, some may experience a sunburn. You might offer protection from the afternoon and midday sun through a shade of a tree or a wall.

Growing the Sulfur cosmos in shady areas is impossible because the larger flowers would require a lot of energy to grow and produce. Always provide the lighting conditions and set them in an area with full sun for best results.

What will happen if Sulfur cosmos gets inadequate sunlight?

When the Sulfur cosmos does not get adequate sunlight, or they are not placed in full sun locations, it's worth noting that the photosynthetic process will slow down. A lack of sunlight will cause the stems to become more leggy since they become thin and long since they tend to seek too much sunlight. They will not bloom and produce seeds in the shade.

Inadequate sunlight will also mean that the older leaves can die, the color of the new ones is lighter than the old foliage, and the new growth is smaller than the last ones.

The Sulfur cosmos indeed loves the sun so much. However, they can wilt when exposed to excessive heat and ultraviolet light during the extreme summer months, so be careful. You might want to cover them with a net that has a green shade, especially in the summer, to prevent the leaves and the flowers from scorching. When they are indoors, reduce the heat with the help of a fan.

Does Sulfur cosmos need special care about sunlight during its different growth stages?

When the Sulfur cosmos is growing, they need more light than their mature counterparts. The younger ones should receive adequate light, but they might not be prepared for sudden full sunlight, especially if they are grown in a nursery. They can be more sensitive to the summer sun, so the lighting should be gradual and slow.

How much light does Sulfur cosmos need for photosynthesis?

During summer or late spring, the Sulfur cosmos needs 6 to 8 hours of direct light every single day. This is whether they are planted outdoors. If the Sulfur cosmos is planted in pots or you're growing them in the winter, they need direct fluorescent lights that help them grow better. Make sure to place them in an indoor area where they are facing south or east so they can have enough sunlight for photosynthesis.

Are there any cautions or tips for sunlight and Sulfur cosmos?

When transplanting the plants, they should not be exposed to sudden sunlight. Give the Sulfur cosmos to grow and mature before transplanting outside. Some species of herbaceous plants can grow taller and might cast a shade on other young plants. Allow between 80 to 100 days of growing season before planting another batch to ensure that every plant receives more than enough sunlight for at least 6 hours a day.

Make sure that the Sulfur cosmos receives the best light possible, especially if it's planted in a nursery. These are sun-loving plants, but too much sunlight with a very hot temperature is also detrimental to their growth. Indoor lights should be replaced with natural sunlight as much as possible since these species crave this every day.

What is the optimal temperature for Sulfur cosmos?

The best temperature for Sulfur cosmos 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 Sulfur cosmos 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 Sulfur cosmos may be able to survive with some help.

During the warmer parts of the year, Sulfur cosmos 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 Sulfur cosmos. Hotter temperatures can cause wilting, drooping, and even sunburn on the leaves, which can be difficult for Sulfur cosmos 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 Sulfur cosmos

If this is the first year of your Sulfur cosmos 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 Sulfur cosmos, 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 Sulfur cosmos 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 Sulfur cosmos 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 Sulfur cosmos 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 Sulfur cosmos 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 Sulfur cosmos from frost or cold damage. If you’re growing Sulfur cosmos 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 Sulfur cosmos 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 Sulfur cosmos 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 Sulfur cosmos

During the cold winter months, Sulfur cosmos 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 Sulfur cosmos, 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 Sulfur cosmos. 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, Sulfur cosmos will be able to resprout at the correct time without any help, but this method increases the chances of a successful second sprouting.

Why do I need to fertilize my Sulfur cosmos?

Plants need nutrients to survive; most gardeners, regardless of experience, are well aware of this factor. However, without food, Sulfur cosmos will die out soon after the first pollination. Therefore, providing the right type of nutrients in the right amounts is the best way to keep Sulfur cosmos going throughout the blooming season and producing large, beautiful flowers.

Fertilizer also helps Sulfur cosmos build a large, healthy root system. This plant needs all the help it can get since its root system is very thin and easily damaged. Fertilizing at planting helps Sulfur cosmos build a solid root structure that not only provides stability to the plant, but also sets the stage for a sensational flowering performance. When timed correctly, fertilization can greatly extend Sulfur cosmos's flowering period.

When is the best time to fertilize my Sulfur cosmos?

Sulfur cosmos puts on tremendous growth early in the growing season, once the danger of the last frost has passed. It’s during this time that Sulfur cosmos should be fertilized; more specifically, during planting. The idea is to apply when the plant is first planted in the ground or in planters; however you choose to plant it. This will be the only dose of fertilizer until later in the year, when blooms are in full force.

Once the season is in full swing and Sulfur cosmos has opened most of its blooms at full size, it’s time to start fertilizing again. Around the time when blooms are at peak output, begin fertilizing again once every three to four weeks, as weather permits. Then, after Sulfur cosmos starts to put out fewer new blooms, stop fertilizing; there’s no need to fertilize when the plant can’t produce any more blooms.

When should I avoid fertilizing my Sulfur cosmos?

While regular fertilizing is important for Sulfur cosmos, it absolutely can be applied at the wrong time. Some situations call for holding back the fertilizer once in a while. These are usually climate related, but they also include a variety of controllable factors. Essentially, when something is wrong with the plant, the soil, or the climate, wait it out until things have been smoothed over and the plant has recovered.

An example of when not to fertilize is if there are severe or unexpected changes in the weather. If a cold nap suddenly comes in the middle of summer, wait until it’s warm again to start fertilizing. The same stands for if the soil becomes too dry or too packed to absorb anything. At this point, fertilizer will be going straight to the roots, rather than being diffused by soil before it reaches them. As you can imagine, the roots of Sulfur cosmos aren’t very fond of that.

When temperatures soar during the hottest parts of the day into the 90-degree fahrenheit range, don’t apply fertilizer. Since fertilizer can be broken down at various speeds depending on temperature, it’s especially important not to allow hot temperatures to break it down too quickly. Pests or diseases should also be treated and cleared up before re-fertilizing.

What type of fertilizer does my Sulfur cosmos need?

Most types of Sulfur cosmos need the same general balance of nutrients from fertilizer. These should come in the form of a fertilizer that’s formulated specifically for high-yield blooming plants. A fertilizer with a higher level of phosphorus is the best option. This type of fertilizer has a higher P number in its NPK number, for example 10-30-10.

Several fertilizer brands sell a fertilizer that’s perfect for blooming plants like Sulfur cosmos, which are an easy and fuss-free way to provide the right nutrients. If you do choose to use a pre-mixed fertilizer, follow the directions on the package to prevent Sulfur cosmos from getting too much or too little fertilizer, both of which can cause the plant to grow poorly or even wilt entirely.

How do I fertilize my Sulfur cosmos?

Depending on the type of fertilizer you have, specific fertilizing instructions may vary. However, there are a few general tips for applying most types of fertilizer to Sulfur cosmos. The first fertilizer application, which should be when you first plant Sulfur cosmos, will likely consist of mixing the recommended amount of fertilizer into the soil before planting and watering in the Sulfur cosmos.

Subsequent fertilizing may look a little different. For pellet fertilizers, simply mix the pellets into the top inch of soil around the outer edge of the plant, where the roots are. Water them in very well at first, then water regularly after that. Other fertilizers may be mixed into a watering can and applied just like a regular watering. Follow any instructions on fertilizer packaging for consistency, but if you’d rather keep things on a regular schedule, shoot for every three to four weeks.

What happens if I fertilize my Sulfur cosmos too much?

Over-fertilizing is a very easy mistake to make for first-time gardeners, or even for experienced gardeners trying out a new product. Fortunately, Sulfur cosmos makes this issue known very well by displaying several signs of distress. You may notice that its leaves are yellowing quickly, the foliage may wilt, or new blooms may be under-developed. These are all clear signs of too much food.

When you fertilize Sulfur cosmos too frequently, you create uninhabitable soil conditions. Soil may become too hot, which is a term used to describe when soil is too saturated with minerals, nutrients, or compost, and ends up burning the roots of anything planted in it. It’s a good idea to flush out the soil well once a month or so, just by watering twice as much as normal with good drainage.

Get tips and tricks for your plants.

Keep your plants happy and healthy with our guide to watering, lighting, feeding and more.

More About How-Tos

Explore 6 of plant how-tos on Feng shui direction, Water, Lighting, Temperature, Transplant, etc.

Feng shui direction

South

The sulfur cosmos carries an inherent affinity towards the South. This affinity is derived from the plant's bold, fiery hues, inciting a natural resonance with the fire element which is predominantly associated with the South direction. This connection, however, is meshed with nuances, encouraging thoughtful placement within your individual space.

Water

Twice per week

Sulfur cosmos comes from regions in North and South America, including Mexico, the Caribbean, and parts of the United States. It is commonly found in open areas, such as fields, roadsides, and disturbed sites. Sulfur cosmos is well-adapted to a variety of climates and soil conditions, but it generally prefers well-draining soil and moderate moisture levels. Its native environment suggests that regular watering is necessary to maintain the soil consistently moist, but it's important to avoid overwatering, as sulfur cosmos can tolerate dry conditions to some extent.

Lighting

Full sun

Sulfur cosmos thrives best under a continuous and substantial exposure to sunlight, and can withstand slightly lesser light conditions. Its place of origin favors conditions with extensive sun, promoting robust development. Overexposure can cause leaf scorch, while too little light hinders their bloom.

Temperature

0 38 ℃

Sulfur cosmos is a plant originally native to regions with temperate climates. It thrives best in a temperature range of 68 to 95 °F (20 to 35 ℃). Adjustments may be required in colder seasons to satisfy its warmth preference.

Transplant

12-15 inches

Transplanting sulfur cosmos thrives when done in the refreshing months of early spring, as it gives the plant ample time to establish before blooming season. Ensure a sunny location with well-draining soil. If needed, provide support to help young plants stabilize during transplanting.

Pollination

Easy

Enchanting bees with its vibrant display, sulfur cosmos relies on these buzzing pollinators to ensure its reproduction. Bees, lured by the plant's striking hue and sweet nectar, perform pollen transfer from the male to the female flower parts. This delightful dance mostly occurs during the day, making a sunny spectacle of sulfur cosmos's pollination process.

Asters bellflowers fanflowers and allies

Common Pests & Diseases

Common issues for Sulfur cosmos based on 10 million real cases

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.

Wilting after blooming

Flowers may wither for a variety of reasons.

Solutions: Check the soil or potting medium. Coarse textures can allow water to drain too rapidly, preventing the plant from taking up enough. If the soil and roots seem very dry, add sphagnum moss or other mediums that hold water. Water according to recommendations for each plant's species. Low humidity can be corrected by misting the plant regularly or placing it near a humidifier. Keeping it near other plants helps, too. Keep the environment consistent in terms of temperature, humidity, and lighting. Keep it away from vents, heaters, and air conditioners, and avoid moving it to locations where it will experience a temperature shock. Hot, dry heat, and cold drafts are problematic for many plants. Especially if the plant is outside, it could be experiencing heat or light stress. Try moving it to a shadier location.

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.

Thrips

Thrips are 1 to 2 mm bugs with slender black or translucent-yellow bodies. They move quickly and feed on the plant's sap.

Solutions: Thrips can be controlled in several ways. Spray plants with Pyrethrin, which is an organic pesticide derived from marigolds (follow label instructions) or Permethrin, the synthetic version of Pyrethrin. Introduce beneficial insects to the garden that eat thrips, such as minute pirate bugs and green lacewings. Remove heavily infested plants from the area and discard. Address viral diseases that may have been transmitted by the pests. For less serious cases -use a hose to spray the thrips off of the plants.

Plant dried up

The entire plant may dry out due to dieback or normal seasonal dormancy.

Solutions: The solution for a dried out plant depends on the cause, so determine the cause before selecting a treatment method. Adjust your watering: Stick your finger in the soil near the roots. If it feels bone dry or overly saturated, you need to adjust your watering frequency accordingly. Prune back dead foliage: Snip off any brown stems and leaves on the plant to make space for new growth. This encourages the roots to send up fresh stems. Move to a proper environment. This may involve decreasing or increasing sun exposure, depending on the species. Decrease fertilizer applications. If you have applied too much fertilizer, you can repot plants with fresh potting soil. Wait. If your plant has dried out as daylight is decreasing, it is entering dormancy. Decrease watering and wait until the plant resumes growth.

Treat and prevent plant diseases.

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

Distribution Map

Habitat

Roadsides

Native

Cultivated

Invasive

Potentially invasive

Exotic

No species reported

More Info

Plant Type

Herb

Flower Color

Yellow

Red

Orange

Bloom Time

Summer, Fall, Early winter

Leaf Color

Green

Name story

Sulfur cosmos||Yellow cosmos||Orange cosmos

Most of the Mexican herbs from the Cosmos genus are featured with radiate heads with various colored flowers and pinnate leaves. Hence, it is given the name cosmos. The plant can sprout different colored flowers such as yellow-orange or yellow sulfur. Therefore, it is called different names like sulfur cosmos, yellow cosmos or orange cosmos.

Symbolism

Young girl's heart

Usages

Garden Use

Sulfur cosmos can be used as flower borders or clustered in flowerbeds. This is a common, popular plant that is used to fill space and add visual appeal with its clusters of bright blooms. Prized for this appearance, it is used to attract a variety of butterflies and hummingbirds to help pollinate and attract predator insects that manage plant pests. They grow well in any region and fit any type of garden, specifically in cutting gardens and cottage gardens. They are often planted with Cannas, whose unique, bright blooms blend well with their own.

Scientific Classification

Phylum

Vascular plants

Class

Dicotyledons

Order

Family

Daisy

Genus

Cosmos

Species

Sulfur cosmos

Find your perfect green friends.

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

Related Plants

Princess flower

The princess flower is native to Brazil and grows best in sunny areas. It has a wide reach when growing, and can be trained to "climb" up trellises or other upright structures. Its leaves are hairy to the touch.

Blackboard tree (Alstonia scholaris) is a perennial evergreen tree that can grow to 40 m tall. It is a tropical tree with fragrant clusters of showy white flowers that bloom in fall. The perfume-like scent of the blossoms is more obvious during the evenings. Most often planted as a street tree. Another common name for this tree is Devil’s tree.

Summer, autumn

Blackboard tree

The asian virginsbower is one species of garden clematis that has generated some incredible beautiful varieties. It is a deciduous vine that produces creamy white to purple flowers according to varieties and blooms in early summer on shoots that developed from the previous year's growth.

Spring, Summer

Asian virginsbower

Summer

Plants of the genus Clematis are often planted in the garden and can also be grown as potted plants. There are a few tips needed to care for them. Most common asian virginsbower are vines and can be used to create flowering walls or decorative arches, as well as being planted alongside trees, shrubs, etc.

Common jasmine

Common jasmine (Jasminum officinale) is a deciduous plant species that flowers in summer. Common jasmine flowers have a strong fragrance. This species is native to the Caucasus, northern Iran, Afghanistan, Pakistan, and the Himalayas.

Spring, summer

Shrubs and vines in the genus Jasminum are famous for their attractive, pale, star-shaped blooms of flowers, distinctive fragrance, and oil. Despite their delicate appearance, they are not difficult to maintain. They tolerate different temperature ranges, but prefer slightly drier soils in combination with a warm, humid environment. However, given the large number of different varieties, it is important to tailor conditions to the variety you choose.

Peace lily

Peace lily (Spathiphyllum cochlearispathum) is a plant species that is native to southern Mexico. Peace lily is commonly cultivated as an ornamental houseplant. This species should not be grown in direct sunlight.

Spring, summer

Spathiphyllum spp. are popular indoor, ornamental plants. They are easy to care for and can grow well with little sunlight. With proper care, they can bloom twice a year for two months or longer. The plant's spathe is mostly white, or light green for a few varieties. Its leaves are elliptic and have dark green, bright surfaces.

Spider plant

The spider plant is a green perennial plant with long, thin leaves that earn it another name, "ribbon plant." It has spread far from its native Africa because it is easy to care for. Since spider plants grow well in partial or full shade, they have become popular houseplants.

Summer

Spider plant is a common ornamental potted plant with good adaptability and simple maintenance. The leaves are green in all seasons. The flowers are white and elegant, showing between spring and summer.

View More Plants

Most Common Herb

Plant Collection Most Common Herb Fragrant plantain lily See More The trademark feature of Asia-native plantain lilies is the numerous glossy oval leaves with deep parallel veins. The Fragrant plantain lily is additionally decorated with strongly fragrant, trumpet-shaped, large white flowers, which are unique in the genus. Hosta plantaginea is one of the favorite cultivatedContinue reading “Most Common Herb”

Plant Collection Best Annual Plant to Grow Common sunflower See More The Common sunflower is recognizable for its bright flower on a very tall stem. It is often grown in gardens. These flowers have been important in culture: they were worshipped by the ancient Inca people, and today, they represent eco-friendly movements. The artist VincentContinue reading “Best Annual Plant to Grow”

Plant Collection Suggested Plants to Build a Garden That Blooms All the Year Round Bearded iris See More BloomTime:Spring The Bearded iris is a flowering plant that appears in many different colors. It is a popular garden plant because it’s easy to grow. Though their native lands are in Europe, Bearded irises are often grownContinue reading “Suggested Plants to Build a Garden That Blooms All the Year Round”

Most Common Herb

Plant Collection Most Common Herb Golden pothos See More The Golden pothos is a popular flowering house plant that’s commonly seen in Australia, Asia, and the West Indies. It goes by many nicknames, including “devil’s ivy,” because it is so hard to kill, and can grow in the dark. Golden pothos has poisonous sap, soContinue reading “Most Common Herb”

17 Easy Annual Flowers that You Can Grow from Seeds

Plant Collection 17 Easy Annual Flowers That You Can Grow From Seeds What could be more natural than pushing a seed into the earth, or scattering a handful across the ground? And yet, we all know the disappointment that can come from planting seeds only to find nothing happening. Don’t let this turn you off fromContinue reading “17 Easy Annual Flowers that You Can Grow from Seeds”

View More Articles

Add to My Garden

Sulfur cosmos

Cosmos sulphureus

Also known as: Orange cosmos, Klondike cosmos

Water

Twice per week

Sunlight

Full sun

Care Guide for Sulfur cosmos

Water

Fertilization

Soil

Sand, Loam, Chalky, Clay, Acidic, Neutral, Alkaline

Potting Suggestions

Yellow cosmos can be transplanted to pots when seedlings grow to 6 to 8 cm.

Sunlight

Full sun, Partial sun

Know the light your plants really get.

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

Download the App

Questions About Sulfur cosmos

Watering

Pruning

Sunlight

Temperature

Fertilizing

What is the best way to water my Sulfur cosmos?

What should I do if I water my Sulfur cosmos too much or too little?

How often should I water my Sulfur cosmos?

How much water does my Sulfur cosmos need?

How can I tell if i'm watering my Sulfur cosmos enough?

How should I water my Sulfur cosmos through the seasons?

How should I water my Sulfur cosmos at different growth stages?

What's the difference between watering Sulfur cosmos indoors and outdoors?

Is pruning necessary for my Sulfur cosmos?

How do I prune my Sulfur cosmos?

Are there any cautions I should be careful with when pruning my Sulfur cosmos?

Are there any tips for pruning my Sulfur cosmos?

When should/shouldn't I prune my Sulfur cosmos?

What should I look for when pruning my Sulfur cosmos in different seasons?

How much sunlight should Sulfur cosmos get per day to grow healthily?

What type of sunlight does Sulfur cosmos need?

Can sunlight hurt plants? How to protect Sulfur cosmos from sun and heat damage?

Should I protect Sulfur cosmos from sun exposure?

What will happen if Sulfur cosmos gets inadequate sunlight?

Does Sulfur cosmos need special care about sunlight during its different growth stages?

How much light does Sulfur cosmos need for photosynthesis?

Are there any cautions or tips for sunlight and Sulfur cosmos?

What is the optimal temperature for Sulfur cosmos?

Temperature requirements for first year or seedling Sulfur cosmos

How can I protect Sulfur cosmos from extreme temperatures?

Dormant season temperature recommendations for Sulfur cosmos

Why do I need to fertilize my Sulfur cosmos?

When is the best time to fertilize my Sulfur cosmos?

When should I avoid fertilizing my Sulfur cosmos?

What type of fertilizer does my Sulfur cosmos need?

How do I fertilize my Sulfur cosmos?

What happens if I fertilize my Sulfur cosmos too much?

Get tips and tricks for your plants.

Keep your plants happy and healthy with our guide to watering, lighting, feeding and more.

Download the App

More About How-Tos

Common Pests & Diseases

Common issues for Sulfur cosmos based on 10 million real cases

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

Wilting after blooming

Flowers may wither for a variety of reasons.

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

Thrips

Thrips are 1 to 2 mm bugs with slender black or translucent-yellow bodies. They move quickly and feed on the plant's sap.

Learn More

Plant dried up

The entire plant may dry out due to dieback or normal seasonal dormancy.

Learn More

Treat and prevent plant diseases.

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

Download the App

Distribution Map

Habitat

Roadsides

Map

Native

Cultivated

Invasive

Potentially invasive

Exotic

No species reported

More Info

Plant Type

Herb

Flower Color

Yellow

Red

Orange

Bloom Time

Summer, Fall, Early winter

Leaf Color

Green

Name story

Sulfur cosmos||Yellow cosmos||Orange cosmos

Symbolism

Young girl's heart

Usages

Garden Use

Scientific Classification

Phylum

Vascular plants

Class

Dicotyledons

Order

Asters bellflowers fanflowers and allies

Family

Daisy

Genus

Cosmos

Species

Sulfur cosmos

Find your perfect green friends.

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

Download the App

Related Plants

Princess flower

Tibouchina urvilleana

Spathiphyllum cochlearispathum

Most Common Herb

17 Easy Annual Flowers that You Can Grow from Seeds