Common Problems With Hollyhock Plants
- Common Hollyhock Insect Infestations Hollyhocks are susceptible to attack by three different insects; hollyhock weevils, Japanese beetles and sawflies. ...
- Diseases to Watch For Rust, leaf spots and anthracnose are three types of fungus that attack hollyhocks. ...
- Severe Weather Damage High winds or torrential rains can damage hollyhocks because of the sheer height of the flowers. ...
- Preemptive Measures to Take ...
What is wrong with my hollyhocks leaves?
Disease. Rust, leaf spots and anthracnose are three types of fungus that attack hollyhocks. Leaf spots start as small gray spots on the leaves of the plant. The disease eats away at the leaf and produces a hole as the infested area falls from the foliage. Rust is a common problem with hollyhocks and can cause the plants to look ragged.
Will hollyhocks die from rust fungus?
Although the plant may not die, you may want to put hollyhocks with rust fungus out of their misery because of the severe disfigurement. Does hollyhock rust spread to other plants? Yes, it does! It only spreads to other members of the Alcea family, so most of your other garden plants are safe.
What kind of bugs live in hollyhocks?
Identifying & Treating Hollyhock Diseases And Pests 1 Rust. Rust is a very common infection that's caused by the fungus Puccinia malvacearum. ... 2 Weevils. Hollyhock weevils are tiny insects that multiply rapidly. ... 3 Cut Worms. Cutworms is the name used for the larvae of many types of moths. ... 4 Slugs and Caterpillars. ...
Do hollyhocks spread Mallow disease?
It only spreads to other members of the Alcea family, so most of your other garden plants are safe. There are mallow weeds that are members of the family that can act as a host reservoir for the disease, so it’s best to keep weeds away from hollyhocks.
How do you treat hollyhock fungus?
Cut down hollyhock plants at the end of the season and burn or bury the debris. Use fungicides if necessary. Chlorothalonil and sulfur are good choices. Apply them every seven to ten days or more often if it rains.
What does rust look like on hollyhocks?
You may see the following symptoms: Bright yellow or orange spots on the upper leaf surface. Reddish-orange to brown, lumpy, spore-producing pustules on the corresponding lower surface. The pustules turn ash-grey under conditions of high humidity, as airborne spores are produced.
What kills hollyhock rust?
If you decide to use fungicides for control, select products that are labeled for use on hollyhocks (or more generally on ornamental flowering plants) and contain the active ingredients chlorothalonil, mancozeb, myclobutanil, tebuconazole, or triticonazole.
How do you keep hollyhocks healthy?
Provide regular water and keep soil moist for starting hollyhocks. However, once well established, they are fairly drought tolerant. Water from below and avoid wetting the foliage, as this can lead to diseased leaves.
Can hollyhocks survive rust?
Management of hollyhock rust Because the rust fungus survives from season to season on infected plants parts, cut back the plant stalks at the end of the season and thoroughly remove all of the stalks, stems, and leaves.
How do you get rid of plant rust naturally?
A weekly dusting of sulfur can prevent and treat rust fungus. Neem oil, a botanical fungicide and pesticide, also controls rust. Some organic gardeners swear by baking soda to control garden fungus. The efficacy of baking soda spray might be enhanced by mixing it with light horticultural oil.
What is eating holes in my hollyhock leaves?
The hollyhock weevil eats small irregular holes in the leaves while Japanese beetles can riddle the leaves with holes eventually skeletonizing them. Knock these pests into a bucket of soapy water to reduce their population and feeding damage. Caterpillars and sawflies can also eat irregular shaped holes in the leaves.
What are the orange spots on my hollyhocks?
Rust fungus is the curse of hollyhocks. The undersides of the leaves are often peppered with bright yellow or orange-red rust spots with corresponding beige-yellow splodges on the upper surface. Eventually, it affects the whole plant, with leaves starting to fall away from the base.
Does copper fungicide work on hollyhock rust?
In cases of severe infection from hollyhock rust, fungicide treatment may be necessary. Fungicides such as sulfur or copper are organic options available commercially at most garden centers or nurseries.
How many years do hollyhocks last?
two to three yearsFirst of all, hollyhocks are a short lived perennial. This means that most varieties will only live two to three years. Their lifespan can be extended some by removing growing hollyhock flowers as soon as they fade.
Should I cut my hollyhocks back?
Prune your hollyhocks in September. By early September, hollyhocks will turn brown, and cutting them down is a good idea. Cutting back hollyhocks will keep their seeds from spreading across your garden, and help the plant survive through the winter.
What to do with hollyhocks when finished flowering?
Pinch off spent blooms and dead leaves regularly to promote more growth and flowers. Toward the end of the growing season, when most of the blooms are finished, you can cut down the main stems of your hollyhocks. If you want the plant to continue coming back year after year, you can leave some seed pods on the stalk.
How do you fix rust on plants?
Use a mild bleach solution, and rinse and dry them thoroughly before putting them away. Rake up and remove fallen or dead leaves and other plant debris. Some gardeners compost vegetation that show signs of rust, expecting the compost pile to heat up enough to kill the spores.
How do you grow hollyhocks without rust?
6 Tips for Growing Hollyhocks and Dealing With Rust1 Start With Rust-Resistant Varieties. ... 2 Grow in a Dry Location with Good Air Flow. ... 3 Water the Roots Not the Leaves. ... 4 Remove Rust-Infected Leaves Immediately. ... 5 Remove Other Susceptible Plants. ... 6 Cut Hollyhocks Down the Ground in Fall.
What is making my hollyhock leaves look like lace?
The leaves of my hollyhocks look like lace. What is causing this and how can I prevent it? Hungry caterpillars, sawflies and Japanese beetles can cause the damage you describe.
What is eating my hollyhock leaves?
The hollyhock weevil eats small irregular holes in the leaves, while Japanese beetles can riddle the leaves with holes eventually skeletonizing them. Knock these pests into a bucket of soapy water to reduce their population and feeding damage.
How to prevent hollyhocks from causing diseases?
Raking up fallen plant matter and debris will help prevent future pests and problems. Watering near the ground will help reduce diseases, as well as keeping proper spacing between each plant.
What causes hollyhocks to have spots on their leaves?
Leaf spot disease is the result of a fungal pathogen attacking the hollyhock causing spots to appear on the leaf surface. These spots range in size from a small dot to covering the entire surface of the foliage. The color of the spots ranges as well and can be yellow, brown, orange or black. This fungal disease generally won’t cause long-term ...
What causes black spots on hollyhocks?
The fungal pathogen that causes anthracnose typically occurs in moist, humid weather and causes black, red or tan spots to appear on the leaves. As the disease progresses, the infected foliage will yellow, wilt and fall from the hollyhock. Anthracnose also results in black cankers appearing on the stems of hollyhocks. Along with proper cultural control, Bordeaux mixture applied to the hollyhock in early spring will help prevent the disease from attacking the plant. Bordeaux mixture is a fungicide containing copper sulfate and hydrated lime, and is used to treat various fungal diseases. Apply the fungicide thoroughly to the hollyhock every seven to 10 days during the plant's active growing period only if the temperatures are below 85 degrees Fahrenheit.
What is Hollyhocks a perennial?
Pest Control. By Amanda Flanigan. Hollyhocks (Alcea rosea) are grown for their large, vibrant flowers that appear on tall flower stalks. This herbaceous per ennial grows in U.S. Department of Agriculture plant hardiness zones 2 through 10 and is commonly used as an annual plant.
Why are my Hollyhock leaves turning brown?
Rust. Rust is caused by a fungal disease that creates brown-, orange- or rust-colored dots or pustules to appear on the hollyhock foliage. If not treated, rust results in wilted and discolored leaves that fall from the hollyhock.
What does it mean when a Hollyhock plant has yellow spots on top?
If you’ve ever tried growing hollyhocks in a hot humid climate you’ve probably seen it—leaves with yellow spots on top and reddish-brown pustules on the undersides that indicate hollyhock rust. If so, we have a few things for you to try before you despair of ever growing this lovely cottage flower successfully.
What is Hollyhock Rust?
Caused by the fungus Puccinia heterospora, hollyhock rust is a disfiguring disease that infects members of the Alcea (hollyhock) family. It begins as yellow spots on top of the leaves with rusty pustules on the undersides.
Where does Hollyhock rust occur?
Hollyhock rust disease occurs anywhere you find hot, humid temperatures. This is especially true in the southeast where these conditions persist throughout most of the summer. Below are some hollyhock rust treatments to try. Bear in mind that you’ll have more success if you employ several of these strategies at once.
What causes yellow spots on the leaves of a sage?
Over time the spots can grow together and destroy large sections of the leaves, causing them to die and drop off. At this point, the stems may also develop spots.
Does Hollyhock rust spread to other plants?
Does hollyhock rust spread to other plants? Yes, it does ! It only spreads to other members of the Alcea family, so most of your other garden plants are safe. There are mallow weeds that are members of the family that can act as a host reservoir for the disease, so it’s best to keep weeds away from hollyhocks.
What is a hollyhock plant?
Printer Friendly Version. Image by Whitney Cranshaw. Hollyhocks are charming, old-fashioned plants easily recognized by the tall spikes of colorful blooms. Although hollyhocks tend to be relatively problem free, they are sometimes plagued by leaf spot diseases, especially when conditions are warm and damp. Rust is the most common.
How to keep hollyhocks from slugs?
A thin layer of fine bark, pine needles, or other mulch will keep rainwater from splashing on the leaves. Limit mulch to 3 inches (7.6 cm.) if slugs are a problem. Thin the plants if the hollyhocks are too crowded. Good air circulation can help prevent hollyhocks with leaf spot and even minimize the disease.
Why do my sage leaves have a shot hole?
As the spots enlarge, the dead tissue in the center may drop out, which give the leaves a “shot-hole” appearance . The spots often run together to cover entire leaves when conditions are moist. In dry conditions, the leaves take on a speckled, tattered appearance.
What are the pests that eat Hollyhocks?
Hollyhocks are susceptible to attack by three different insects; hollyhock weevils, Japanese beetles and sawflies. The gray-colored weevil looks similar to an overgrown tick with a long snout. The mouth on the snout bores through the flower buds so the female can lay eggs. The larvae eat the developing seed while the flower blooms. The result is a lack of seeds for the following year. Japanese beetles love the large leaves of the hollyhock plant and create unsightly holes in the foliage. The hibiscus sawfly looks like an elongated housefly with an orange spot just below the head. The larvae of these pests eat the foliage and can completely destroy the leaves on several plants in a short time. Insecticidal soaps and beetle traps generally aid in ridding the hollyhocks of the pests.
What is the most deadly fungus on hollyhocks?
The damaged leaves will fall off as the disease progresses. The most deadly of the fungi for hollyhocks is anthracnose. This fungus infects the entire plant, including the roots. Control fungi through proper removal and disposal of infected plants and with a general fungicide.
How to keep hollyhocks healthy?
Water at the base of the flowers instead of overhead to keep the foliage dry; wet foliage is a breeding ground for fungus. Remove any insects or infested leaves as soon as possible to keep your hollyhocks healthy throughout the growing season.
Why do my hollyhocks have spots on their leaves?
Leaf spots start as small gray spots on the leaves of the plant. The disease eats away at the leaf and produces a hole as the infested area falls from the foliage. Rust is a common problem with hollyhocks and can cause the plants to look ragged. Brown, yellow or orange spots appear as the fungus forms and grows.
What is the orange spot on my Hollyhocks?
The hibiscus sawfly looks like an elongated housefly with an orange spot just below the head. The larvae of these pests eat the foliage and can completely destroy the leaves on several plants in a short time. Insecticidal soaps and beetle traps generally aid in ridding the hollyhocks of the pests.
Why do hollyhocks need a trellis?
High winds or torrential rains can damage hollyhocks because of the sheer height of the flowers. The stalks are strong, but can be knocked around by a summer storm. A trellis positioned behind the hollyhocks gives you a place to anchor the plants. Garden twine, looped around the stalk and fastened to the trellis, keeps the hollyhocks in place when strong winds hit the garden.
Is Hollyhock a perennial or biennial?
Pest Control. By Julie Richards. Alcea rosea, more commonly known as hollyhock, is a native of China and considered a short-lived perennial or biennial. Hollyhocks grow in U.S. Department of Agriculture hardiness zones 5 through 9. The plant reseeds itself and will produce new plants every year.
What is the color of the bumps on the leaves of Hollyhock?
Brown to dark-red bumps on the undersurface of leaves is typical of hollyhock rust. (Pic- Tom Creswell, Purdue Univ)
What is Hollyhock rust?
Hollyhock rust is the most common fungal leaf disease of hollyhocks (Alcea rosea). Many other ornamentals (e.g., flowering maple, rose mallow) and weeds (e.g., common mallow) in the mallow family are also susceptible. Hollyhock rust can quickly spread, causing stunting of plants and premature leaf drop. In rare instances, hollyhock rust can result ...
How to tell if hollyhock rust is a rusty plant?
Initial symptoms of hollyhock rust are orange to yellow spots (roughly ⅛ to ¼ inches in diameter) on lower leaves. Irregular brown areas may also develop on stems.
Where does Hollyhock rust come from?
Where does hollyhock rust come from? Hollyhock rust is caused by the fungus, Puccinia malvacearum which can be introduced into a garden by windborne spores or on infected transplants. Further localized spread of spores is possible by wind, by splashing rain, or by splashing water from a sprinkler. Warm and humid temperatures favor the growth of the fungus. P. malvacearum can survive the winter in hollyhock leaf and stem debris.
How to save a Hollyhock plant from rust?
If you observe the disease very early in its development, remove symptomatic leaves and dispose of them in your municipal garbage (where allowed) or by deep burying them. Consider follow-up fungicide treatments (although such treatments will be most effective when applied before any symptoms appear). If you decide to use fungicides for control, select products that are labeled for use on hollyhocks (or more generally on ornamental flowering plants) and contain the active ingredients chlorothalonil, mancozeb, myclobutanil, tebuconazole, or triticonazole. When making more than one application, DO NOT use the same active ingredient for all treatments. Instead, alternate the use of at least two active ingredients with different modes of action to help minimize problems with fungicide-resistant variants of the hollyhock rust fungus. Myclobutanil, tebuconazole and triticonazole have similar modes of action and should NOT be alternated with one another. Be sure to read and follow all label instructions of the fungicides that you select to ensure that you use products in the safest and most effective manner possible.
What is the most common hollyhock?
The most common species of hollyhock found in gardens is Alcea rosea, known as the common hollyhock. Many cultivars of this species are available, with some being more rust-resistant, taller, or cold-hardy than others.
When do hollyhocks bloom?
The bristly hollyhock (Alcea setosa): Flowering earlier than the common hollyhock, this species typically blooms from April to June, grows in USA hardiness zones 5 to 9, and the blooms are pink.
How long do hollyhocks last?
Tall hollyhocks are perfect for adding height and floral interest in a cut flower vase. They typically last a week to ten days once cut.
Do Hollyhocks self seed?
Hollyhocks readily self-seed and, if you already have them in your garden, new plants will likely pop up the following year without any effort on your part. If you want to introduce them to your garden, growing them from seed isn't difficult. Follow these general tips for a more successful germination rate, but always check temperature and timing specifics for each species or cultivar:
Can Hollyhocks survive in shade?
Most hollyhocks can survive in partial shade, but they generally prefer a full sun position. These tall plants can flop in overly shady locations. If you live in a particularly hot and dry region, a partial shade location will prevent the lower leaves on your hollyhock from withering.
What are the characteristics of hollyhocks?
Hollyhocks come in a wide variety of colors: blue, pink, purple, red, white, yellow and even black. The tall spikes are covered with blooms from top to bottom. Hollyhock leaves are large, coarse and palmate in shape.
How long do Hollyhocks last?
Many of the most common varieties are biennials, meaning they complete their lifecycle over 2 years. The first year is spent growing foliage and storing energy.
How to start Hollyhocks from seed?
Hollyhocks are easily started from seed indoors or out. Seeds can be sown directly outdoors about a week before last frost. Sow at just ¼ inch deep and about 2 feet apart. Hollyhocks have long taproots, so if seeds are started indoors, use tall, individual pots and transplant early to avoid damage. Start indoor seeds about 9 weeks before the last average frost date. Seedlings can be placed outside two to three weeks after the last frost. Also, bear in mind that some are biennials and may not bloom until their second year.
What is the darkest hollyhock?
The darkest of the Spotlight series, this almost black hollyhock is a standout in the garden. Other colors in the series are red, pink, yellow and white. This variety behaves more like a short-lived perennial than a biennial.
Do Hollyhocks attract bees?
Hollyhocks support the lifecycle of painted lady butterflies as a host plant for their caterpillars and also attract other pollinators such as bees and hummingbirds. If you’ve got a cottage garden, it’s just not complete without a few hollyhocks gracing the edges.
Do Hollyhocks need to be cut back after flowering?
Other than staking and cutting the stalks back after flowering, hollyhocks really don’t require much maintenance , but they do need to be protected from insects and fungal diseases such as rust. Hollyhocks support the lifecycle of painted lady butterflies as a host plant for their caterpillars and also attract other pollinators such as bees and hummingbirds. If you’ve got a cottage garden, it’s just not complete without a few hollyhocks gracing the edges.
Do Hollyhocks self seed?
Hollyhocks are best, and easiest, grown from seed and they will readily self-seed if flower stalks are left in place.
What is the curse of Hollyhocks?
Do Time to act in December. Rust fungus is the curse of hollyhocks. The undersides of the leaves are often peppered with bright yellow or orange-red rust spots with corresponding beige-yellow splodges on the upper surface. Eventually, it affects the whole plant, with leaves starting to fall away from the base.
How to get rid of hollyhock rust?
Remove infected leaves from plants as soon as the fungus is seen. In winter, when the hollyhock dies down, clear away any infected leaves as they will harbour the fungal infection. Weeds such as common mallow, which are related to hollyhocks, also harbour rust so pull them out if they appear in the garden.
What is the most common disease in Hollyhocks?
Hollyhock rust is the most common disease of hollyhocks. There are few pest problems with hollyhocks but one of the most common is called hollyhock rust. This disease causes rust-colored blisters to develop along the stems and all over the leaves. It usually does not kill the plants but certainly makes them look ugly.
What are the colors of hollyhocks?
They now come in a variety of flower colors ranging from reds, pinks, whites, yellow and nearly black burgundy. The flowers can also be single or double.
Do Hollyhocks bloom every year?
Most of the old-fashioned types of hollyhock are biennial which means that if you plant them from seed in your garden, they will usually not flower until the second year. And then, unfortunately, the plants will usually die. But, if you let some of the plants go to seed , you will probably get new plants to grow and start having them bloom every year. Some of the newer varieties are considered perennial so that they will more often survive for several years. If you remove the flowers right after they are done blooming, this will give the plants a better chance to come back again the next year because they did not use as much of their stored food reserves to produce seed.