How to Plant, Grow and Care For Hollyhocks
Thinking of adding some hollyhocks to your garden this season? These popular garden shrubs can make a visually stunning addition to any garden! In this article, gardening expert Paige Foley walks through everything you need to know about hollyhocks and their care.
When you think of country cottage gardens, what plant comes to mind? For me, it’s hollyhocks. Growing up, I remember seeing them around old farm houses and century old barns. They are a symbol of simpler times. These eye-catching towers of flowers come in a number of colors that will bloom all season long.
Hollyhock is known for being very tall. Most varieties are around 6-8 feet tall. Some can get even taller under the right conditions. There are newer varieties that are smaller around 4 to 5 feet in height. Because of their tall stature, they work best along buildings, fences or in the back of a flower bed.
Hollyhocks are considered biennials but may seem like a perennial. They produce thousands of seeds per season and those seeds drop into the soil and regrow in the spring. If you are interested in adding hollyhocks to your garden, keep reading for all the information you need to get started.
Hollyhocks Plant Overview
Plant Type Biennial
Plant Spacing 18 inches +
Native Area Asia and Europe
Sunlight exposure Full sun to partial shade
Plant height 8 feet +
Water requirements Low
Plant Depth Seeds: 1-2 inches
Hardiness Zone 3-8
Soil Type Rich, moist
Pest Spider Mites, Thrips, Beetles
Attracts Hummingbirds, Butterflies, Bees
They are native to China but quickly spread their way to the middle east by the time of the Crusades. The seed was eventually brought to England where it earned its place in many cottage gardens.
Mallow is the common name given to members of the althea family. The hoc portion of hollyhock comes from the medicinal properties of the plant. It was commonly used to soothe swollen heels of horses. Nowadays, it’s commonly found on old farmstead properties but is gaining popularity in home gardens.
Hollyhocks are very tall and produce large, delicate blooms. They can reach heights of over 8 feet tall but there are shorter varieties as well. This makes them a great choice for borders in the garden or along buildings and fences.
They bloom starting in mid-summer with numerous flowers on tall stems. Many varieties are biennials. This means they complete their life cycle in 2 years.
Certain biennial varieties will not bloom until their second year. The first year is all about growing foliage and energy storage for blooms. By year 2, the stalks will shoot up and flowers and seeds form.
Hollyhock may seem like a perennial because they so readily drop their seed. Their seed drops straight down where the previous stalk grew. This process continues for years to come. Once they are established, they are pretty low-maintenance.
Hollyhocks are naturally deer resistant. This is why they have been a popular choice in farmyards. The deer may not like them but hummingbirds, bees, and butterflies love them. Plant at the back of a pollinator garden to give some dramatic height while also attracting beneficial pollinators.
Hollyhocks grow in hardiness zones 3 to 8. They can withstand some pretty cold conditions which makes them a great choice in northern regions of the United States. Their seeds are able to stay dormant in cold soils until spring when conditions are ideal.
If planting in regions that experience harsh winters, consider covering the area to protect the seed. Mulch is an excellent insulator and will help protect the seed that has fallen to the ground during the winter. You could also use grass clippings or dead leaves as a barrier from the cold as well.
Hollyhock may be able to grow in zones above an 8 but be cautious of the daytime heat. Consider planting in partial shade and water regularly. Morning sun would be ideal in higher zones because it’s less intense. Afternoon sun can be too intense, and they may die quickly.
When to Plant
You have options when it comes to planting. They can be planted in the fall or spring! There are benefits to both. Let’s discuss the benefits of planting in either season.
Planting in the fall is going to give you a head start to the growing season and saves time in the spring. Typically, seed that’s planted in the fall will produce more plants than in the spring. Sow the seeds about a week before the last frost of the fall. Once soil temperatures and conditions are ideal, the seed will begin to grow in the spring.
Spring planting can also be done but is a little more time-consuming. The seeds should be planted indoors 6 to 9 weeks before the last frost. They love warmer soils so plant seedlings 2 to 3 weeks after the last frost.
As biennials they won’t produce a bloom until the second year. Some varieties may produce bloom in their first year if planted early enough in the spring. The most northern zones will likely not produce bloom in the first year.
The growing window is so short that they won’t have enough heat and light to produce a bloom when first established. Once established, you should start to have a good rotation of new and older growth.
How to Grow
If sowing your seed in the fall, begin by sowing ¼ inch deep and 2 feet apart. Once your hollyhocks become established, they will reseed on their own in the fall. You will have to thin them out if they are becoming overcrowded. Overcrowding won’t allow enough airflow between plants and will create a breeding ground for disease.
If you are planting seeds in the spring, start by placing seeds into large, deep containers either in your home or in a greenhouse. Hollyhocks have a large taproot and need deep containers to ensure proper growth. Once outdoor conditions are ideal, transplant into the soil.
Ambient temperatures should be around 70-75° F to initiate proper germination. Keep the seedlings well watered and in direct sunlight. A few weeks after the last frost, plant the seedlings outdoors about 2 feet apart. It will take 10 to 14 days for the seed to germinate.
Hollyhocks aren’t a great choice for containers. They need the support of other plants, buildings or fences to stand up. There are a few shorter varieties that may survive in containers but may need to be stacked or leaning against a wall.
They have a large root system and need a very large container to support them. Keep this in mind if you decide to plant hollyhock in a container.
Occasionally, you might be able to find hollyhock sold as a bare root or in a container from a local garden center. If you purchase a bare root or a container, plant them in early spring or late fall a week or 2 before the last frost. Identify a location and dig holes to place the bare root or plant into. Water well and watch them grow.
The great thing about hollyhocks is that they tolerate a range of climates. Hardy even in the coldest climates, they can withstand temperatures in the single digits. However, early frost can damage the plant and really set them back. Ideal, daytime temperatures are 65 to 90 F.
They are fairly drought tolerant but if conditions are too hot and dry for too long, they can shut down. If you are experiencing dry conditions for weeks on end, consider watering often to keep foliage and bloom production going.
Excessive humidity can also be a problem. This is a breeding ground for diseases. Be sure plants have plenty of space between each other. This will promote good air circulation and prevent the development of future diseases.
Since hollyhocks are so tall and delicate, they are easily damaged by the wind. If you live in winder regions of the United States, choose a location that has some protection. You can also stack them to prevent them from bending in the wind.
Hollyhocks are very versatile plants and can handle a range of sunlight requirements. The more sunlight the better. They will grow wonderfully in partial shade as well. They need a minimum of 4 hours of sunlight per day but 6 to 8 hours is ideal.
If planting in higher zones, consider planting in partial, morning sun. This will protect the plant from the intense afternoon sun.
Planting in fewer hours of light will stunt their growth. There will be fewer blooms and foliage will be less vigorous. Be mindful of the location you choose for planting. Sunlight will play a huge part in how well they grow.
Hollyhocks need regular waterings to keep soils moist during the beginning stages of growth. Once they are established, they are rather drought tolerant. Consider watering if your region is experiencing prolonged periods of hot and dry conditions.
Hollyhocks don’t like soggy soil conditions, specifically in the winter. Soggy soils will cause root rot and the plant will fall because of its weak root system created by the rot. Always water towards the bottom. Watering over the leaves can cause leaves diseases to grow and spread quickly.
Hollyhocks are versatile plants and can grow in most soil types. As long as you have rich, well-draining soil, hollyhocks will thrive. Sandy and clay soils have a tendency to leach important nutrients.
Typically you need to add organic matter to these soils to help hold nutrients. If you believe your soils aren’t suitable for hollyhocks, consider adding organic matter.
You don’t have to spend a ton of money on organic matter from a store or garden center. Most likely you have organic matter right at home. A few examples of organic matter are dead leaves, grass clippings and kitchen scraps. Incorporate your organic matter of choice to improve the overall health of your soil.
Hollyhocks thrive in soils with an abundance of nutrients. Without proper nutrients, you may notice yellowing leaves and less impressive blooms. If you already have dark, nutrient-rich soils, hollyhocks will thrive without any additional fertilizer.
If you are concerned about your soil’s lack of nutrients, consider adding a plant specific organic matter or a fertilizer. Your local garden center should be able to help choose the right fertilizer for your region and plants.
Maintenance & Care
When it comes to maintenance and care, these shrubs are fairly hands-off. Deadheading is always a good idea to encourage new blooms. Most varieties will be able to get by with just an occasional pruning. Harvesting seeds for future plantings, and overwintering are also an important part of hollyhock maintenance.
Deadheading your hollyhocks isn’t necessary but can be proven to be beneficial. It keeps the blooms going longer through the growing season. It will also make the plant look cleaner. By removing the spent flowers, the plant puts less focus in seed production and more into bloom production.
To remove the spent flowers, pinch or cut the faded or finished blooms before the seed pods form. This will encourage more blooms throughout the growing season. Remember, hollyhocks are biennial and need new seeds to drop in the soil for new growth.
Towards the end of the season before the plant dies, leave some of the spent flowers on the stalk. The seed will drop into the soil and new plants will emerge the following spring. This is important because if you remove all flowers before they produce seed, you will have minimal new growth in the spring.
If you are interested in harvesting the seed to plant in a new location or give to friends or family. Here are some helpful tips to make harvesting a breeze.
Once the flowers on the hollyhock plant are faded and finished they will begin to produce seeds. If allowed to stay off the plant, the seed will drop into the ground and germinate in the spring. If you want to collect seeds before they drop, you’ll have to watch your plants and act quickly before the seed drops.
Once the seeds are mature enough to harvest, the pod will turn brown. The pod should fall over easily and this is your true sign that the pod is done and good to harvest.
Place the seeds in an envelope or container and be sure to label the variety on the outside. Store in a dark place until you’re ready to plant.
If you live in colder regions of the United States, you may have to do a little work to get your hollyhock ready for winter. Start by cutting the stems and leaves to the ground level before winter, this will help clean the area and prevent diseases from spreading.
Next, if you live in frost-prone environments, consider adding a layer of protection over the root zone. Mulch and straw is an excellent method of protection but dead leaves and grass clippings work as well.
In the spring, remove whatever you choose to cover them with to allow the new shoots to grow. Each winter is different and covering your hollyhock seeds will give them the best chance at survival.
As with all plants, there are a number of common issues that gardeners will face once hollyhocks have been planted in the garden. Let’s take a look at some of the most common issues, which typically can result as some type of pest or disease.
This is a very common disease found on hollyhock. It is caused by the Puccinia Malvacearum fungus. The rust will be orange-brown in color and appear as flecks on the undersides of the leaves. The flecks will get larger as the disease spreads and eventually the tops of leaves will turn yellow.
The fungus spreads rapidly when moist, humid conditions are present. The disease starts on the lower leaves and works its way up the plant. This is due to the bottom leaves being closer to the soil where moisture is more abundant.
If left untreated the leaves will dry up, turn brown and die. The most effective way to control the disease is to spray a copper fungicide. Your local garden center should carry this and be sure to follow label instructions.
One of the easiest diseases to identify because it leaves a white powdery coating on the leaves and stem. This disease develops in hot, humid conditions combined with dry soils.
Powdery mildew typically does not affect hollyhocks until later in the growing season. This fungus produces spores and will overwinter on plant debris. When removing infected plants, do not leave them laying in the same area as healthy plants.
Ways to prevent the spread of powdery mildew is to ensure all plants have plenty of airflows. Remove plants if they appear crowded to encourage proper airflow. Watering plants in the early morning will allow soils to dry throughout the day and control the spread of the disease.
One of the most common nuisances in the garden is the spider mite. They are very hard to see and if you see tiny white dots covering the leaves, the damage is already done. Spider mites love hot and dry conditions and plants suffering from water-related stress.
Spider mite damage will spear as small yellow or brown spots on the leaves. If the plant has extensive damage, the leaves will turn yellow and growth will stop. Spider webbing can also be seen on the plant if the infestation is significant.
These beetles are unique, unlike the other insects that defoliate leaves. Japanese Beetles are skeletonizing pros. This means they will eat between the veins of the leaves and if damage is extensive the plant will die.
The beetle has unique, two-tone coloring. The upper half is an emerald green and the lower half is copper brown. The entire beetle will have a metallic sheen to it.
There are a number of popular hollyhock varieties to choose from. Many have different flower colors, or different growing profiles depending on your planting location. Let’s look at some of the most popular.
This is an heirloom variety and one of the oldest on the market. Beautiful, deep maroon blooms tower above the garden at a height of 5 to 8 feet. Their bloom color is almost black, as the name implies. They have a white center that peers out from the bell shaped flower. This is a classic variety to bring cottage core vibes to any yard.
‘Chater’s Double Violet’
This is a beautiful hollyhock has light violet blooms with a pink hue. ‘Chater’s Double Violet’ can reach up to 4 to 7 feet in height. Plant in full sun to experience blooms from mid-summer to fall. Naturally, they are deer resistant which is why they have been commonly planted in rural settings.
This variety has a vibrant, light pink to dark pink ruffled edge bloom. This hollyhock is sure to bring the party to any flower bed. This is one of the shorter hollyhock and when mature is only 4 feet tall. Since they are smaller they would work well in a low flowerbed or container.
This variety is a pale lemon yellow with a small white center. ‘Sunshine’ has a mature height of 5 to 6 feet and will flower in its first year when planted very early in the spring. This variety will attract hummingbird, butterflies and bees so it’s a great choice in pollinator gardens.
Frequently Asked Questions
How long do they bloom?
They will bloom from mid-summer to late fall. Depending on the time of planting and spring conditions, blooms can begin a bit sooner. If this is your first year growing hollyhock, some varieties will not bloom till the 2nd year.
Does hollyhock spread?
Hollyhock spreads quickly when new seed drops to the ground. Allow 2 or more feet between plants when first established to allow room for growth. Pruning during the season will help control how quickly they spread as well.
Why won’t my hollyhock bloom?
Take a look at where it’s planted. Are they receiving enough light? Remember, they can handle partial shade but prefer full sun. Also, take a look at the soil. Is it too wet or too dry? Hollyhock are relatively drought tolerant but may need additional watering in prolonged periods or drought. If soils are too wet, consider adding organic matter to increase drainage.
Can you transplant hollyhock?
You can transplant them when they are not blooming, preferably in fall or winter. Dig around the roots and gently lift from the soil. Place in a bucket of water until you are ready to plant. Plant in a sunny location and water well.
Hollyhock are treasured for their old time feel and beautiful blooms. They are easy to grow once they are established and really low-maintenance. Plant along a building or fence to add a pop of color. Remember, the blooms grow towards the top of the plant so consider placing shorter plants in front to cover their long stems. Good luck and happy planting!