Cultivation and History
The common hollyhock (Alcea rosea) is a flowering biennial or short-lived perennial from the Malvaceae plant family.
If you cut back the flower stalks after the blooms fade, these plants can live for a few years in Zones 3 to 9.
They say that this species of hollyhock is from Asia. The plant’s common name, “holy hoc” or “holy mallow,” refers to the place where it was first introduced to Europe, which is thought to be Palestine.
Hollyhocks were introduced to Europe in the mid-1500s, where they quickly became popular due to their vibrant colors. Today, they are a cottage garden staple.
There are so many hollyhocks growing now, it’s hard to believe that a fungus once threatened their cultivation. People stopped growing wheat in 1869 due to a destructive rust disease.
Hollyhocks became popular again in 1891 when horticulturists developed varieties that were resistant to disease.
When to Plant Hollyhocks
You will need to decide when to plant your hollyhock seeds based on when you want the plants to bloom. Hollyhocks typically bloom in the middle of summer and early fall. Although you won’t see flowers during their first year, if you give them enough time to grow, you will see them the following year.
Planting Seeds Outdoors
Hollyhock seeds take a long time to germinate, so it’s best to start them early in the season.
You can plant seeds directly in the ground one week before the last frost date. You should check the weather forecast often so you know when it is a good time to plant. If you plant too soon, the cold temperatures may stop the seeds from germinating. It is recommended to plant in the spring for those who have severely cold winters.
If you live in a climate with long warm summers and mild winters, you may prefer to sow seeds in late summer. This will enable you to have lovely flowers next summer provided the plants have enough sunny days to grow.
Planting Seeds Indoors
Sprouting hollyhocks from seed indoors then transplanting them outdoors will let you have them earlier than if you just waited to sow the seeds directly in the ground Fill individual pots or cells with soil and plant the seeds. Place grow lights above the pots or cells to provide them with full sun.
Start seeds indoors in seed-starting cell trays a couple of months before planting transplants. You should plant your seeds in late winter or early spring if you want them to grow in the spring. For a transplant in the fall, planting seeds in mid-to-late summer should be enough time.
How to Plant Hollyhocks
Hollyhocks can be planted in many types of soil, as they are not fussy. They’re happy with clay, loam, or sandy soils. To ensure your seeds have the best chance of survival, you should choose a fertile soil or seed starting mix. The pH level of the soil should be between 6.0 and 8.0.
Hollyhocks can be grown in containers using a potting mix. Apply compost or fertilizer to the ground in spring to help the flowers grow.
Make sure to choose soil that won’t allow water to pool and remain stagnant so your hollyhocks will have a better chance at thriving.
New plants need to be kept moist by watering them more frequently than mature plants. Do not let water accumulate or the ground to become dry when your flowers are still growing. If you choose well-drained soil, they can tolerate frequent watering. Make sure your containers for growing seeds have drainage holes in the bottom.
Avoid getting the leaves wet when you water. Rust disease is a fungal infection that can damage your hollyhocks. To prevent rust disease, it is important to keep water from coming into contact with the soil.
After you transplant hollyhock flowers, water them more often than usual for one or two months. Give the plants approximately 2.5 centimeters of water per week. After the plants have settled in their new location, you will not need to water them as often.
The following text is a mature hollyhock’s tolerance of dry soil. If you have to skip watering for a few days, they should survive with less water.
Hollyhocks need at least six hours of direct sunlight to flourish. Zucchinis grow best when they have access to both sunlight and water. They can survive in partial shade, but they will not thrive.
If you live in a hot area, your flowers might need partial shade to prevent them from getting too much sun. Overexposure to the sun can cause flowers and leaves to become damaged. Placing your plants in a shady area will help to protect them from the sun’s harmful rays. A row cover can provide shade for trees or buildings.
If you want to protect your hollyhocks from the heat, you need to give them at least six hours of sunlight.
Use a rake to loosen the soil before planting the seeds outdoors. This will help them grow better as compacted soil can hinder their growth. If you want a flower bed full of blooms, you’ll need to scatter the seeds evenly. You don’t need to cover the seeds with soil, and they should be no more than ¼ inch deep below the surface. You can choose to lightly cover them with a thin layer of soil if you’d like. If you live in an area with strong winds or have a lot of birds, it may be safer to cover them.
To plant seeds, make a small hole in the soil and plant 1-3 seeds in it. To plant the seeds, you can cover them with a thin layer of soil. If more than one seed is planted in the same spot, the seedlings will need to be thinned out.
Water your seeds gently so that the water does not puddle up. Move them around as you water them. This is especially important for scattered seeds outside. The germination process may take a few weeks, so be patient. Keep the soil moist during this time.
Managing Pests and Diseases
Although common hollyhocks are not very susceptible to pests or diseases, they can sometimes have problems.
Here are a few of the main ones to look out for:
Hollyhocks can experience pest damage to their leaves and flowers, but they are resilient. The damage is not severe and can be fixed using different methods.
The most effective way to manage pests is to grow a diverse ecosystem that will attract beneficial insects. Scanning your plants for pests and using either cultural or physical controls can assist in keeping them looking great.
The most common pests that you may encounter include:
The insects mentioned puncture plant stems in order to suck out the nutrients in the form of sap. This action can inadvertently spread diseases.
The honeydew left behind by aphids can be appealing to ants and can lead to sooty mold.
You can help control the aphid population by growing plants that attract ladybugs, green lacewings, and birds. In the event that aphids are present on your plants, you have a few options for removal. spraying them with water from a hose is one option. If the infestation is more severe, you could mix a small amount of soap with water and apply it to the affected area.
Due to their nocturnal feeding habits, earwigs are sometimes considered pests. They are active at night and will feast on just about anything, from tender petals of flowers to ripe fruits. If you see holes in leaves that look like they were munched on by an insect, this could indicate the presence of earwigs.
You can find these big beetles eating the leaves or flowers of your plants. The best way to eliminate them is to pick them off one by one and place them in a container with a lid.
If you have chickens, you can feed them Japanese beetles or take them to a friend who has a flock and likes to give their birds treats.
This refers to insects that are commonly found in gardens and come out at night when the weather is damp. They leave a slimy trail behind and large holes in leaves.
They are easy to catch when there are not a lot of them, but you have to go out at night. I have successfully summoned many to a shallow tray filled with leftover beer. I have found that this is an effective method for summoning entities.
The signs of spider mites attacking your plant include cotton-like webbing that causes leaves to curl. The tiny white dots on the leaves indicate where the insect was sucking on the plant juices.
They thrive in dry conditions and can quickly spread, causing leaves to turn yellow and dry out.
miticides like Grower’s Ally Spider Mite Control, consisting of a blend of botanical oils, can be used at any stage of the plant’s growth to get rid of these pests.
Spray is available for purchase from Amazon in 24-ounce bottles. It can also be used to feel better if you have them. It can also be used to stop them from happening.
The hollyhock weevil is so closely associated with hollyhocks that it is named after them. These are tiny black beetles with orange-colored legs.
If you notice that the leaves of your hollyhock are turning into lace during the months of June and July, it is possible that the culprit is a weevil!
Pests like to eat leaves and buds during the summer, and they will often congregate on the buds, flowers, and seed pods. Female weevils lay their eggs inside seed pods, where the hatched larvae will feed.
If you shake a plant that an adult weevil is on, the weevil will fall off. To get rid of them, put a big piece of cloth under the plant, give it a shake, and then scoop up the bugs to put them in a bowl of soapy water, which will kill them.
Hollyhocks aren’t susceptible to many diseases. Some fungi can cause diseases in plants which need to be managed carefully.
Alternaria Leaf Spot
The spots caused by this fungal infection are often mistaken for rust spots, but you can tell the difference by the type of spots you see.
While Alternaria may cause superficial rusting on the top of the leaf, it does not cause the same level of rusting on the underside. The spots are small and angular, and they are a grayish color. They are spread out over the leaves. The holes will eventually kill the plant tissue, leaving the plant behind.
If you see signs of this disease on a plant, cut off the affected parts right away to help stop the disease from spreading. Fungicides can help prevent the growth of Alternaria.
Hot, humid weather creates an ideal environment for the disease to spread. The Anthracnose fungi attack everything from the roots to the leaves including the stem and petioles.
If Anthracnose is not identified and stopped quickly, it can spread quickly and kill hollyhocks.
Loose, black spots will form on the leaves and stems of infected plants. These spots can also be tan or red. The spots on the leaves will turn slimy and pink, and the stems will also develop black cankers. The leaves on the tree will start to wilt and turn yellow before they eventually drop off.
To prevent the spread of this disease, cut off the infected parts of the plant and then treat the plant with a fungicide according to package directions.
If you have seen a white powder on top of the leaves, it is most likely powdery mildew. That’s powdery mildew!
This disease is caused by a fungus and can start if a plant becomes stressed due to a lack of water. High relative humidity increases the possibility of infection. The fungus spreads through spores that do well in dry conditions.
Fungal spores are easily spread through the air, so it is important to remove infected leaves as soon as signs of the disease are noticed.
The best way to avoid spreading spores while removing foliage affected by powdery mildew is to bring a trash bag with you to the infected plant so you can carefully place leaves in the bag and then quickly tie it up. This will prevent the spores from being released into the air and infecting other plants.
Wear gloves and either wash them afterwards or use disposable gloves.
This fungal disease is very common in hollyhocks. The rain doesn’t harm the flowers, but the plant itself looks a little beaten up.
The best way to prevent rust is by watering at the soil level. Wet conditions encourage the spread of this disease.
This disease is characterized by yellow spots on the top side of leaves and rust-colored raised spots on the underside of leaves and along stalks.
If the fungus is widespread, you may need to remove all the leaves and treat the plant with a fungicide. In severe cases, it might be necessary to remove the entire plant.
There are no rust-resistant hollyhock varieties available at the moment, though the common hollyhock has been improved over time.
If you would like to choose a hollyhock that is rust-resistant, you should select resistant cultivars of other species, such as A. ficifolia (the fig-leaved hollyhock) or A. rugosa (the Russian hollyhock).
Spraying your plants with a biofungicide (e.g. Bacillus subtilis) can help to prevent or treat fungal infections.
Sold as CEASE, it’s available at Arbico Organics. This biofungicide helps to control the spread of pathogens, and it is safe for pollinators.