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Add to My Garden Black-eyed susan
Rudbeckia hirta
Also known as: English bull's eye, Gloriosa daisy
The black-eyed susan is a flowering black and yellow plant with curving leaves. It is culturally important in the Southern U.S., and is often used to attract butterflies to gardens. It long ago spread throughout North America and much of the world. Black-eyed susan is the state flower of Maryland and was important in the history of the University of Southern Mississippi.
4 to 10
Hardiness Zones
Weeds
Care Guide for Black-eyed susan
Water
Black-eyed susan is adapted to grow in drought conditions, but to ensure that your plant grows well you should water it during dry periods. Be sure to only water the plant when the surrounding soil is dry since overwatering will cause it to rot. Also, water the plant only at the base, since it is prone to damp-related diseases.
Fertilization
Black-eyed susan gets all the nutrients that it needs from the soil and water, so it doesn't require the addition of any artificial fertilizers to thrive. However, using mulch on the surrounding soil is a great way to retain moisture and introduce nutrients naturally.
Pruning
Deadhead (or remove) withered flowers after flowering.
Soil
Loam, Chalky, Acidic, Neutral, Alkaline
Potting Suggestions
Needs excellent drainage in pots.
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Black-eyed susan
Water
Twice per week
Sunlight
Full sun
Hardiness Zones
4 to 10
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Black-eyed susan
Water
Twice per week
Sunlight
Full sun
Hardiness Zones
4 to 10
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Black-eyed susan
Water
Twice per week
Sunlight
Full sun
Hardiness Zones
4 to 10
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Questions About Black-eyed susan
Watering 
Pruning 
Sunlight 
Temperature 
Fertilizing What is the best way to water my Black-eyed susan?
When watering the Black-eyed susan, 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 Black-eyed susan 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.
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What should I do if I water my Black-eyed susan too much or too little?
Both overwatering and underwatering will be detrimental to the health of your Black-eyed susan, 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 Black-eyed susan, 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 Black-eyed susan have become brittle and brown.
It is crucial that you notice the signs of overwatering as soon as possible when caring for your Black-eyed susan. 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 Black-eyed susan 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 Black-eyed susan is receiving too little water, all you need to do is water more regularly until those signs have subsided.
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Free
How often should I water my Black-eyed susan?
If your plant is in a pot. The most precise way to decide whether your Black-eyed susan 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.
If you grow your Black-eyed susan 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 Black-eyed susan can show an admirable ability to withstand drought.
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Free
How much water does my Black-eyed susan need?
When it comes time to water your Black-eyed susan, 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.
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How should I water my Black-eyed susan at different growth stages?
The water needs of the Black-eyed susan can change depending on growth stages as well. For example, when your Black-eyed susan 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 Black-eyed susan 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 Black-eyed susan 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 Black-eyed susan more water at this time.
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How should I water my Black-eyed susan through the seasons?
The Black-eyed susan 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 Black-eyed susan will contract a disease.
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What's the difference between watering my Black-eyed susan indoors and outdoors?
It is most common to grow the Black-eyed susan 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 Black-eyed susan 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 Black-eyed susan 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.
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More Questions People Also Ask
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Common Pests & Diseases
Common issues for Black-eyed susan based on 10 million real cases
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.
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.
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.
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.
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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.
Overview
Leaf beetles range in size from 1.5 mm to 2 cm. Both adult beetles and their larvae eat the leaves of many different types of plants. There are over 35,000 different species of leaf beetles, in a variety of colors including gold, green, yellow-striped, and red striped. Some of these have been mistaken for ladybirds because of their shape and coloring. They can be oval, round, or elongated in shape. These insect pests are most active in spring and summer.
If not controlled, leaf beetles can do a lot of damage to vegetable crops and ornamental plants. They feed on the leaves, flowers, stems, roots, and fruits of different plants. They can fly, which means it's easy for them to move from one plant to another. Some species of leaf beetles only target one specific crop, while others will target many different types of plants. Although a lot of the damage that they cause is cosmetic, an infestation can weaken a plant and leave it prone to other more problematic diseases.
Symptom Analysis
The first signs of a leaf beetles infestation are small visible holes in leaves. Leaves then become discolored and dark beetle droppings can be seen. As the leaves turn yellow and brown, they will drop off the plant onto the ground. Some leaves will appear skeletonized with only the veins still remaining.
Infestation begins in spring, when the adult beetles emerge from the soil and lay their eggs on the leaves of plants. When these eggs hatch, the young nymphs start munching on the leaves as they grow up. Once leaf beetles are large and mature, they'll fall to the ground and pupate in the soil over winter before starting the cycle all over again.
Leaf beetles also eat holes in fruits and vegetables. These can be seen as small round holes that sometimes have a larger brown area surrounding them.
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.
Prevention
To prevent infestations of leaf beetles, follow these practices.
- Regularly check for beetles. To prevent large pest infestations, be proactive about frequently checking plants for pests and removing them quickly.
- Clear debris. Clear weeds and debris to remove areas where these beetles may overwinter and hide.
- Attract natural predators. Birds and other insects, such as wasps and ladybugs, are effective natural predators of leaf beetles. Encourage them to visit by including a diverse array of plants to provide habitat and food. Also, avoid applying broad-spectrum herbicides that can harm and kill beneficial insects.
- Plant aromatic herbs like mint, garlic, or rosemary, as these can repel leaf beetles.
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Wilting after blooming
Flowers may wither for a variety of reasons.
Overview
Wilting after blooming is sometimes a natural aging process of the flower, while other times it may indicate a problem. Orchids, for example, can bloom for anywhere from two weeks to three months, so wilting after a few days signals a problem for most varieties. This can happen to virtually any ornamental flowering plant, but those with shallow roots and limited tolerance for drought, full sun, and low humidity are more susceptible.
This is a common problem, and often has an easy fix. Sometimes, however, it is the result of more serious causes such as pests or disease of the root system.
Symptom Analysis
- At first, flowers may look a little limp.
- Petals may start to appear dried out and turn brown.
- Eventually they may drop off the plant all together.
Disease Cause
Wilting blooms can be a sign of an unhealthy root system. Any condition that prevents the plant from absorbing enough water and nutrition can result in wilting blooms and sometimes other symptoms. If the plant doesn’t have enough water, it cannot maintain appropriate pressure within stems, leaves, and blooms, causing them to wilt.
This can result from physical damage – for example from root breakage during re-potting or attack by insects like cutworms. If you recently re-potted your plant, physical damage to the roots is a likely cause. If you see insects, they may be eating leaves, roots, or flowers. Fungal infections can also cause root rot and damage, preventing water and nutrient uptake.
Finally, wilting blooms can result simply from age. If no other symptoms are visible, it may simply signal the natural end of the flower’s lifespan. If it seems premature, this may be caused by environmental factors: water, humidity, light, or stress. Under-watering is a common cause. Similarly, plants adapted to high humidity dry out easily when humidity is low, like during winter or in dry climates. Too much light can also stress plants that need shade, causing blooms to wilt.
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.
Prevention
- Read up on moisture, light, and soil type preferences for each plant to avoid underwatering, incorrect light levels, or other conditions that can cause wilting blooms.
- Avoid re-potting during the flowering period. This causes additional stress on the plants because they need to repair root damage and adapt to the new micro-environment, all of which can result in wilting.
- One other potential cause is ethylene gas, a plant hormone related to ripening. Some fruits and vegetables emit ethylene, especially bananas. Apples, grapes, melons, avocados, and potatoes can also give it off, so keep flowering plants away from fresh produce.
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Brown spot
This infection can cause brown spots or patches to appear on the plant.
Overview
Discolored spots on the foliage of plants are one of the most common disease problems people observe. These spots are caused by fungal and bacterial diseases, with most infections related to a fungal pathogen.
Brown spot can occurs on all houseplants, flowering ornamentals, vegetable plants, and leaves of trees, bushes, and shrubs. No plants are resistant to it, and the problem is worse in warm, wet environments. It can occur at any point in the life stage as long as leaves are present.
Small brownish spots appear on the foliage and enlarge as the disease progresses. In severe cases, the plant or tree is weakened when the lesions interrupt photosynthesis or cause defoliation.
Symptom Analysis
In most cases, brown spot only affects a small percentage of the whole plant, appearing on a small amount of the leaves. A small infection only puts minor stress on the plant. However, if left untreated and the disease progresses over numerous seasons, it will severely impact the health and productivity of the infected specimen.
- Sporulation begins (reproduction of the fungal spores), and tiny spots appear on leaves.
- Placement is often random and scattered as diseases are spread through raindrops.
- May appear on lower leaves and the interior of the plant where humidity is higher.
- Brown spots enlarge and grow large enough to touch neighboring spots to form a more prominent blotch.
- Leaf margins may turn yellow.
- Tiny black dots (fruiting bodies of the fungi) appear in the dead spots.
- Blotches grow in size until the entire leaf is brown.
- The leaf falls off the plant.
Severe Symptoms
- Partial or complete premature defoliation
- Reduced growth
- Increased susceptibility to pests and other diseases
Disease Cause
Brown spot, or leaf spot, is a common descriptive term given to several diseases affecting the leaves of plants and trees. Around 85% of diseases exhibiting leaf spots are due to fungus or fungus-like organisms. Sometimes brown spot is caused by a bacterial infection, or insect activity with similar symptoms.
When conditions are warm and the leaf surfaces are wet, fungal spores being transported by wind or rain land on the surface and cling to it. They do not rupture the cell walls but grow in the space between the plant plasma membrane and the plant cell wall. As the spores reproduce, they release toxins and enzymes that cause necrotic spots (i.e., dead tissue) on the leaves, allowing the fungi to consume the products released when the cells degrade.
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.
Prevention
Like many other diseases, it is easier to prevent brown spot than cure it, and this is done through cultural practices.
- Clear fall leaves from the ground before winter to minimize places where fungi and bacteria can overwinter.
- Maintain good air movement between plants through proper plant spacing.
- Increase air circulation through the center of plants through pruning.
- Thoroughly clean all pruning tools after working with diseased plants.
- Never dispose of disease plant material in a compost pile.
- Avoid overhead watering to keep moisture off of the foliage.
- Keep plants healthy by providing adequate sunlight, water, and fertilizer.
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Aged yellow and dry
Natural aging can cause leaves to turn yellow and dry out.
Overview
Regardless of the type of plant or where it is grown, at some point, it will begin to aged yellow and dry. This is a natural, unavoidable process that happens when the plant has completed all of the steps in its life.
Annual plants go through this process at the end of a single growing season. Perennial plants live for multiple years, if not tens or hundreds of years, but will still ultimately exhibit these symptoms.
Symptom Analysis
When plants have progressed through their natural developmental stages and are nearing the end of their lifecycle, they begin showing signs of decline. Leaves will start to yellow and droop, and over time they turn papery brown and dry.
Once completely dry, the leaves begin to fall from the plant until the entire plant has dried out.
Disease Cause
At the end of its life, genetic coding within the plant increases the production of ethylene, a phytohormone that controls senescence or natural aging and death. Cell division stops, and the plant begins catabolizing resources to use in other parts of the plant.
As this happens, the tissues begin yellow and drying until the entire plant is desiccated and perishes.
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.
Prevention
Unfortunately, there is no way to prevent plants from dying of “old age.” To help prolong their life, and put off symptoms of aged yellow and dry for as long as possible, take care of them by giving them enough water, fertilizing them appropriately, and making sure they get enough sunlight.
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Weed Control
Weeds
Black-eyed susan is native to North America. Although it is not invasive in the sense of taking over non-native habitats, black-eyed susan can still spread uncontrollably and cause issues in areas where it has been planted as a decorative plant. Black-eyed susan is troublesome as it can spread through its seeds and its rhizomatous roots, and once it gets well established, it is difficult to get rid of. It can colonize disturbed areas where there has been recent damage to the terrain, e.g., after a fire or messy mowing. The plant can survive repeated mowing or cutting to the ground, and can even produce seed in maintenance regimes with long periods between mowing, but is not able to flower or set seed in regularly mowed lawns.
How to Control it
The best time to remove weeds is before bearing fruits. Pulling out: For a kind of herb, wear gloves or use tools to dig weeds. Pruning: For an annual plant, pruning its aboveground parts can effectively control the growth. Plowing: Plow the soil before cultivation and bury the whole weed in the soil. Chemical control: If in large amounts, weeds can be removed by the herbicide.
Do you have weeds in your garden?
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Distribution Map
Habitat
Parks, gardens
Native
Cultivated
Invasive
Potentially invasive
Exotic
No species reported
More Info
Plant Type
Herb
Flower Color
Yellow
Orange
Red
Gold
Bloom Time
Late spring, Summer, Fall
Name story
Black-eyed susan
The name comes from a poem by John Gay, who portrayed black-eyed Susan (Rudbeckia hirta) and sweet William (Dianthus barbatus) as humans to tell a love story, and the name Black-eyed Susan is still in use today. Although its stamen is not really black, it is actually brown colored.
Symbolism
Justice, Impartiality, Strength, encouragement, breaking bad habits
Usages
Garden Use
The widespread wildflower, black-eyed susan, is a welcome addition to courtyard gardens. They are prized for their bright, cheerful beauty, adding a golden glow to gardens. They are also often seen in prairie and cottage gardens, where they attract a wide variety of pollinators. The beauty of this plant pairs very well with other prairie flowers such as the butterfly weed and the purple coneflower.
Scientific Classification
Related Plants
Annual fleabane
While native to North America, the annual fleabane has been introduced to other places around the world, as well as in 43 states of the United States. It is a popular choice for bees, flies, wasps, and butterflies as a source of nectar, but is invasive and is threatening the native ecosystem where they grow.
Bull thistle
Bull thistle (Cirsium vulgare) is a thistle plant native to Europe, Africa, and Asia. Bull thistle produces a large amount of nectar and attracts pollinators. Bull thistle is considered a noxious weed in areas of Europe and Australia.
African tulip tree
African tulip tree (Spathodea campanulata) is an evergreen tree that grows best in full sunlight and well-drained soil. African tulip tree is shade tolerant. African tulip tree is a fast-growing tree and a prolific seed producer. It disperses seeds that can germinate without light, giving it the potential to become invasive in some areas.
Earleaf acacia
Earleaf acacia (Acacia auriculiformis) is an evergreen tree that can grow from 20 to 27 m tall. It is a fast-growing tree with a gnarly trunk and is often multi-stemmed. It blooms in spring with yellowish-orange spiked clusters. Each tree produces about 47,000 seeds per year. It is becoming an invasive tree, displacing vegetation and native plants.
Sessile Joyweed
The sessile Joyweed (Alternanthera sessilis) is an aquatic plant that spreads vigorously from a prominent, very deep taproot. It is listed as a noxious weed in the United States and can devastate small ponds with its aggressive foliage growth. The sessile Joyweed is so dense, it can, in fact, block drainage canals with vegetation and clog irrigation lines!
Japanese meadowsweet
Japanese meadowsweet is considered by many to be an invasive species due to its ability to spread rapidly, creating a dense thicket or hedge. The species traces its roots to Japan, Korea, and China and was introduced in other areas because of its attractive flowers. Use caution when planting to make sure that this shrub can be managed appropriately.
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About
Care Guide
Care FAQ
Pests & Diseases
Weed Control
Distribution
More Info
Related Plants
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Add to My Garden Black-eyed susan
Rudbeckia hirta
Also known as: English bull's eye, Gloriosa daisy
4 to 10
Hardiness Zones
Weeds
Care Guide for Black-eyed susan
Water
Black-eyed susan is adapted to grow in drought conditions, but to ensure that your plant grows well you should water it during dry periods. Be sure to only water the plant when the surrounding soil is dry since overwatering will cause it to rot. Also, water the plant only at the base, since it is prone to damp-related diseases.
Fertilization
Black-eyed susan gets all the nutrients that it needs from the soil and water, so it doesn't require the addition of any artificial fertilizers to thrive. However, using mulch on the surrounding soil is a great way to retain moisture and introduce nutrients naturally.
Pruning
Deadhead (or remove) withered flowers after flowering.
Soil
Loam, Chalky, Acidic, Neutral, Alkaline
Potting Suggestions
Needs excellent drainage in pots.
Tips, advice, and instructions for over 13,000 species that you will find nowhere else
Black-eyed susan
Rudbeckia hirta
Water
Twice per week
Sunlight
Full sun
Hardiness Zones
4 to 10
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Questions About Black-eyed susan
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Common Pests & Diseases
Common issues for Black-eyed susan based on 10 million real cases
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.
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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.
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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.
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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.
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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.
Overview
Leaf beetles range in size from 1.5 mm to 2 cm. Both adult beetles and their larvae eat the leaves of many different types of plants. There are over 35,000 different species of leaf beetles, in a variety of colors including gold, green, yellow-striped, and red striped. Some of these have been mistaken for ladybirds because of their shape and coloring. They can be oval, round, or elongated in shape. These insect pests are most active in spring and summer.
If not controlled, leaf beetles can do a lot of damage to vegetable crops and ornamental plants. They feed on the leaves, flowers, stems, roots, and fruits of different plants. They can fly, which means it's easy for them to move from one plant to another. Some species of leaf beetles only target one specific crop, while others will target many different types of plants. Although a lot of the damage that they cause is cosmetic, an infestation can weaken a plant and leave it prone to other more problematic diseases.
Symptom Analysis
The first signs of a leaf beetles infestation are small visible holes in leaves. Leaves then become discolored and dark beetle droppings can be seen. As the leaves turn yellow and brown, they will drop off the plant onto the ground. Some leaves will appear skeletonized with only the veins still remaining.
Infestation begins in spring, when the adult beetles emerge from the soil and lay their eggs on the leaves of plants. When these eggs hatch, the young nymphs start munching on the leaves as they grow up. Once leaf beetles are large and mature, they'll fall to the ground and pupate in the soil over winter before starting the cycle all over again.
Leaf beetles also eat holes in fruits and vegetables. These can be seen as small round holes that sometimes have a larger brown area surrounding them.
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.
Prevention
To prevent infestations of leaf beetles, follow these practices.
- Regularly check for beetles. To prevent large pest infestations, be proactive about frequently checking plants for pests and removing them quickly.
- Clear debris. Clear weeds and debris to remove areas where these beetles may overwinter and hide.
- Attract natural predators. Birds and other insects, such as wasps and ladybugs, are effective natural predators of leaf beetles. Encourage them to visit by including a diverse array of plants to provide habitat and food. Also, avoid applying broad-spectrum herbicides that can harm and kill beneficial insects.
- Plant aromatic herbs like mint, garlic, or rosemary, as these can repel leaf beetles.
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Wilting after blooming
Flowers may wither for a variety of reasons.
Overview
Wilting after blooming is sometimes a natural aging process of the flower, while other times it may indicate a problem. Orchids, for example, can bloom for anywhere from two weeks to three months, so wilting after a few days signals a problem for most varieties. This can happen to virtually any ornamental flowering plant, but those with shallow roots and limited tolerance for drought, full sun, and low humidity are more susceptible.
This is a common problem, and often has an easy fix. Sometimes, however, it is the result of more serious causes such as pests or disease of the root system.
Symptom Analysis
- At first, flowers may look a little limp.
- Petals may start to appear dried out and turn brown.
- Eventually they may drop off the plant all together.
Disease Cause
Wilting blooms can be a sign of an unhealthy root system. Any condition that prevents the plant from absorbing enough water and nutrition can result in wilting blooms and sometimes other symptoms. If the plant doesn’t have enough water, it cannot maintain appropriate pressure within stems, leaves, and blooms, causing them to wilt.
This can result from physical damage – for example from root breakage during re-potting or attack by insects like cutworms. If you recently re-potted your plant, physical damage to the roots is a likely cause. If you see insects, they may be eating leaves, roots, or flowers. Fungal infections can also cause root rot and damage, preventing water and nutrient uptake.
Finally, wilting blooms can result simply from age. If no other symptoms are visible, it may simply signal the natural end of the flower’s lifespan. If it seems premature, this may be caused by environmental factors: water, humidity, light, or stress. Under-watering is a common cause. Similarly, plants adapted to high humidity dry out easily when humidity is low, like during winter or in dry climates. Too much light can also stress plants that need shade, causing blooms to wilt.
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.
Prevention
- Read up on moisture, light, and soil type preferences for each plant to avoid underwatering, incorrect light levels, or other conditions that can cause wilting blooms.
- Avoid re-potting during the flowering period. This causes additional stress on the plants because they need to repair root damage and adapt to the new micro-environment, all of which can result in wilting.
- One other potential cause is ethylene gas, a plant hormone related to ripening. Some fruits and vegetables emit ethylene, especially bananas. Apples, grapes, melons, avocados, and potatoes can also give it off, so keep flowering plants away from fresh produce.
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Brown spot
This infection can cause brown spots or patches to appear on the plant.
Overview
Discolored spots on the foliage of plants are one of the most common disease problems people observe. These spots are caused by fungal and bacterial diseases, with most infections related to a fungal pathogen.
Brown spot can occurs on all houseplants, flowering ornamentals, vegetable plants, and leaves of trees, bushes, and shrubs. No plants are resistant to it, and the problem is worse in warm, wet environments. It can occur at any point in the life stage as long as leaves are present.
Small brownish spots appear on the foliage and enlarge as the disease progresses. In severe cases, the plant or tree is weakened when the lesions interrupt photosynthesis or cause defoliation.
Symptom Analysis
In most cases, brown spot only affects a small percentage of the whole plant, appearing on a small amount of the leaves. A small infection only puts minor stress on the plant. However, if left untreated and the disease progresses over numerous seasons, it will severely impact the health and productivity of the infected specimen.
- Sporulation begins (reproduction of the fungal spores), and tiny spots appear on leaves.
- Placement is often random and scattered as diseases are spread through raindrops.
- May appear on lower leaves and the interior of the plant where humidity is higher.
- Brown spots enlarge and grow large enough to touch neighboring spots to form a more prominent blotch.
- Leaf margins may turn yellow.
- Tiny black dots (fruiting bodies of the fungi) appear in the dead spots.
- Blotches grow in size until the entire leaf is brown.
- The leaf falls off the plant.
Severe Symptoms
- Partial or complete premature defoliation
- Reduced growth
- Increased susceptibility to pests and other diseases
Disease Cause
Brown spot, or leaf spot, is a common descriptive term given to several diseases affecting the leaves of plants and trees. Around 85% of diseases exhibiting leaf spots are due to fungus or fungus-like organisms. Sometimes brown spot is caused by a bacterial infection, or insect activity with similar symptoms.
When conditions are warm and the leaf surfaces are wet, fungal spores being transported by wind or rain land on the surface and cling to it. They do not rupture the cell walls but grow in the space between the plant plasma membrane and the plant cell wall. As the spores reproduce, they release toxins and enzymes that cause necrotic spots (i.e., dead tissue) on the leaves, allowing the fungi to consume the products released when the cells degrade.
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.
Prevention
Like many other diseases, it is easier to prevent brown spot than cure it, and this is done through cultural practices.
- Clear fall leaves from the ground before winter to minimize places where fungi and bacteria can overwinter.
- Maintain good air movement between plants through proper plant spacing.
- Increase air circulation through the center of plants through pruning.
- Thoroughly clean all pruning tools after working with diseased plants.
- Never dispose of disease plant material in a compost pile.
- Avoid overhead watering to keep moisture off of the foliage.
- Keep plants healthy by providing adequate sunlight, water, and fertilizer.
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Aged yellow and dry
Natural aging can cause leaves to turn yellow and dry out.
Overview
Regardless of the type of plant or where it is grown, at some point, it will begin to aged yellow and dry. This is a natural, unavoidable process that happens when the plant has completed all of the steps in its life.
Annual plants go through this process at the end of a single growing season. Perennial plants live for multiple years, if not tens or hundreds of years, but will still ultimately exhibit these symptoms.
Symptom Analysis
When plants have progressed through their natural developmental stages and are nearing the end of their lifecycle, they begin showing signs of decline. Leaves will start to yellow and droop, and over time they turn papery brown and dry.
Once completely dry, the leaves begin to fall from the plant until the entire plant has dried out.
Disease Cause
At the end of its life, genetic coding within the plant increases the production of ethylene, a phytohormone that controls senescence or natural aging and death. Cell division stops, and the plant begins catabolizing resources to use in other parts of the plant.
As this happens, the tissues begin yellow and drying until the entire plant is desiccated and perishes.
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.
Prevention
Unfortunately, there is no way to prevent plants from dying of “old age.” To help prolong their life, and put off symptoms of aged yellow and dry for as long as possible, take care of them by giving them enough water, fertilizing them appropriately, and making sure they get enough sunlight.
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Weed Control
Weeds
Black-eyed susan is native to North America. Although it is not invasive in the sense of taking over non-native habitats, black-eyed susan can still spread uncontrollably and cause issues in areas where it has been planted as a decorative plant. Black-eyed susan is troublesome as it can spread through its seeds and its rhizomatous roots, and once it gets well established, it is difficult to get rid of. It can colonize disturbed areas where there has been recent damage to the terrain, e.g., after a fire or messy mowing. The plant can survive repeated mowing or cutting to the ground, and can even produce seed in maintenance regimes with long periods between mowing, but is not able to flower or set seed in regularly mowed lawns.
How to Control it
The best time to remove weeds is before bearing fruits. Pulling out: For a kind of herb, wear gloves or use tools to dig weeds. Pruning: For an annual plant, pruning its aboveground parts can effectively control the growth. Plowing: Plow the soil before cultivation and bury the whole weed in the soil. Chemical control: If in large amounts, weeds can be removed by the herbicide.
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Distribution Map
Habitat
Parks, gardens
Map
Native
Cultivated
Invasive
Potentially invasive
Exotic
No species reported
More Info
Plant Type
Herb
Flower Color
Yellow
Orange
Red
Gold
Bloom Time
Late spring, Summer, Fall
Name story
Black-eyed susan
The name comes from a poem by John Gay, who portrayed black-eyed Susan (Rudbeckia hirta) and sweet William (Dianthus barbatus) as humans to tell a love story, and the name Black-eyed Susan is still in use today. Although its stamen is not really black, it is actually brown colored.
Symbolism
Justice, Impartiality, Strength, encouragement, breaking bad habits
Usages
Garden Use
The widespread wildflower, black-eyed susan, is a welcome addition to courtyard gardens. They are prized for their bright, cheerful beauty, adding a golden glow to gardens. They are also often seen in prairie and cottage gardens, where they attract a wide variety of pollinators. The beauty of this plant pairs very well with other prairie flowers such as the butterfly weed and the purple coneflower.
Scientific Classification
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