Hollyhocks are well known for their ability to completely envelope a garden with colorful blooms that last all season.
These biennials (more like perennials) are super easy to grow.
They have short stems with tons of flowers that can be everything from pink to black. They even can produce both double or single blooms.
They’re capable of growing up to 10 feet tall. So if you want to pack out your cottage garden with color, this is it.
Let’s learn about how to grow and care for hollyhocks!
Quick care guide: Hollyhock
|Plant type||Biennial herbaceous flowering plant of the hibiscus|
|Scientific name||Alcea rosea|
|Other names||Alcea rosea, Alcée Rose, Althaea ficifolia, Althaea rosea, Passerose, Rose Mallow, Rose de Mer, Rose Papale, Holyoke, Malvaceae, Althea Rose, Hollyhock Flower, Malva, Malva Flower, Malvae Arboreae Flos|
|Soil type||Organic, rich, well-draining, nutrient-rich, wet, chalky, sandy, loamy, acidic.|
|Soil pH||5.5-8.0 (slightly acidic to basic)|
|Sunlight requirement||Full sun for zones 3-8
Partial shade for warmer zones
|Bloom season||Summer (June to August), but can be early summer to late fall|
|Colors||Dark green, lime green, purple, blue, yellow, white, red, black, orange|
|Max height||10 feet|
|Max width||3 feet|
|Low temperature tolerance||5F|
|High temperature tolerance||80F|
|Ideal temperature range||60-70F|
|Humidity||Moderate (50% or higher), spritz with water if needed to bump it, avoid levels too high because this can contribute to rust|
|Watering requirements||1-3 inches per week, adjust for rain or drought, established plants require less water because they're drought tolerant|
|Fertilizer requirements||Balanced, general purpose plant food|
|Plant food NPK||10-10-10 or 20-20-20|
|Days until germination||14-28 days|
|Days until harvest||Not harvestable, seeds can be collected from seed pods|
|Bloom time||March, April, May, June, July, August|
|Speed of growth||Moderate|
|Hardiness zones||USDA hardiness zones 3-10|
|Plant depth||From seeds: 0.25 inches|
|Plant spacing||2 feet apart|
|Don't plant with||Plants that have opposing care requirements|
|Propagation method||From seed, self seeding, transplants|
|Common pests||Snails, slugs, beetles, spider mites, Japanese beetles, hollyhock weevils, caterpillars, sawflies, aphids, worms, fleas|
|Common diseases||Puccinia malvacearum, rust, fungus,|
|Grown in container||Yes|
|Care level||Minimal to none (Easy to care for once you get the hang of it, good for beginners)|
|Best uses||Void fill, background plant, cottage gardens, perimeter plant, climbing plant|
What are hollyhocks?
Hollyhocks are a classic garden staple.
They’re a mid-summer blooming biennial with large, gorgeous flowers on tall stems. Some species behave like perennials and flowers in the first year, but most will flower in the second year.
They’re very popular in cottage gardens, especially along the perimeter. No cottage garden is complete without some hollyhocks on the outside edge.
They also bring in hummingbirds, butterflies, and other pollinators to your garden. Put denser plants in front of the hollyhock to hide their legs but let the pretty flowers shine.
They make an impressive background plant. It pairs well with shorter companion plants like roses or dahlias.
They’re also the favorite for painted lady ladybugs. Bees also like the easy-to-access pollen of the single hollyhocks, but the doubles give you that full look.
Why are they called hollyhocks?
Hollyhocks get their name from the horse hooves during wartimes.
It’s speculated that the Hollyhocks from horses were collected by soldiers during the Middle East crusades. But there’s no real evidence of the nomenclature.
They can tower above your garden and make an excellent background plant with their ability to grow up to 10 feet!
Are they perennials? Or annuals? Or biennials?
Hollyhocks are biennials, meaning that they produce flowers throughout 2 seasons.
But it depends on where you’re located. Cooler zones will only produce annuals, while other zones can produce flowers for multiple seasons, so some people grow them as perennials.
There’s no need to replant every season. These guys will do well if you give them some TLC.
Is hollyhock easy to grow?
Hollyhock is easy to grow and suitable for beginners. Other than regular pruning and deadheading, they don’t need other maintenance.
However, they are susceptible to pests or rust which can damage the plant if not cared for. For the most part, this plant is set and forget.
Expect gorgeous flowers 2 seasons from planting.
The main thing to note is that they don’t like being moved around once established because of their roots. It’s hard to uproot it and put it somewhere else so make sure to choose the right location the first time you plant it.
What do hollyhocks look like?
Hollyhocks have a special signature of single or double cup-shaped flowers that have very few stalks. They bloom on tall spikes above their sea of green foliage.
The flowers can be many colors, with the most popular ones being pink, purple, green, blue, black, yellow, white, red, or hybrids.
The spikes have blooms on the entire length of it. The foliage of the hollyhock is large with a palmate shape.
Are they poisonous?
Hollyhock isn’t known to have any adverse effects if ingested. But it can cause skin irritation due to the fibers on the leaves if touched.
Regardless, you should avoid ingesting it or handling it without protective equipment. Some people or pets may be sensitive to hollyhock. So you never know.
Types of hollyhock plants
There are over 60 confirmed species of hollyhock around the world. The most popular one that you see in cottage gardens is Alcea Rosea.
But others have different colors, patterns, heights, and tolerate various temperatures. The majority of hollyhocks are perennial or biennial, all that reach upwards of 8 feet tall.
If you’re looking for popular hollyhock species, this list should get you started:
- Bristol hollyhock (flowers earlier than other species, grows in zones 5-9, pink flowers)
- Russian hollyhock (less cold hardy, yellow blooms, rust resistant)
- Charter’s Double (common hollyhock, double flowering, variety of colors, blooms constantly through the season)
- Blacknight (semi-double to single flowers that are black, true perennial)
- Halo Bush
- Peaches and Dreams
- Creme De Cassis
- Majorette Mix
How to propagate hollyhock
Hollyhock can be propagated traditionally from seed, or it can be purchased from the local nursery and then put into the garden.
Sure, growing from seed is more rewarding. I’ll give you that. But it also takes much longer (double the time) to see those pretty flowers compared to buying them pregrown from the garden center.
It depends on what YOU want. Let’s go over both methods of propagation.
These plants will self-seed, so you don’t need to propagate them ever again if you grow your first batch. New plants will come out the following season on their own.
That’s how easy it is to propagate hollyhock. However, getting the first hollyhock up and running is the hard part.
This section covers some basic techniques for propagating hollyhock from seed.
You’ll find that germinating it is extremely easy as it has a high germ rate, unlike some other plants (like Virginia creeper).
If you want to start from seed, you can buy a pre-grown hollyhock. Just make sure it has a biodegradable container so it can be planted without uprooting. These plants do NOT like to be moved around once established.
Hollyhock seeds should be planted indoors using a seed starter kit. If you’re in the right zone, you can even sow it directly into the garden if you wish.
The nice part about this plant is that the seeds aren’t finicky. Just give them the right temperature, light, and water for them to thrive.
Sow seeds during the second half of spring if you’re sowing indoors
If sowing in the garden, do it in early summer.
Start sowing using a seed starter kit. Place each seed 0.25” deep into each seed space. Sow 1-2 seeds per compartment. Cover with a light dusting of high-quality potting mix. Water well.
Then cover with a humidity dome. The seed must be kept moist, but never wet. Place the seed kit near a dappled source of light.
Start indoors about 8-10 weeks before the last frost date. Seeds should be moved outside to the garden as early as possible after you harden them off.
This is because hollyhock seedlings have extensive root systems, so they need room to grow. Thin to the strongest plants. Seedlings can be placed outside 2 weeks after the last frost.
Note that you should harden them off by slowly acclimating them to the outside elements. Don’t just put them out there because they can suffer from plant shock.
Hollyhocks are easiest to grow from seed in the second season. They also will self seed if you leave them in their place. So it’s like setting it once and you’re good to go.
Just dedicate a space in your garden for them to flourish. Ideal temperatures for germination are 60-70F. If sowing seeds in the fall, overwinter in a greenhouse and they should flower next season.
You can start them inside a greenhouse if you wish. This will help keep the humidity maintained. Use a bit of potting mix and very lightly firm the seeds. You can even pre-germinate the seeds to get a head start.
Seeds should be kept at 70F. They’ll germinate within 14-28 days on average.
Sowing in the garden
Hollyhock can be sown directly into the soil if you‘re in zones 3-8. These plants fare well when directly sown because they have long roots.
By planting directly outside, they get the room they need to grow right away. Plus, there’s no need to harden them off.
No plant shock. No transferring. Easy, right?
Sow each seed ¼ inch deep into high-quality, well-draining garden soil. Space each seed 2-3 feet apart.
These plants need room to grow and this will minimize soil competition. Since they have those lengthy roots, they need space to grow. Water them so they stay moist. Use a soil meter if you don’t know when to water.
If you purchased one from the nursery, you’ll need to uproot it to move it into your garden. This will harm the plant because they don’t take well to being uprooted and moved to a new environment.
Because of this, you should buy one that is in a biodegradable pot so you can plant it with minimal disturbance.
Where to plant hollyhocks
Choose an area that’s well-draining with full to partial sunlight. Because they’re so tall, you should avoid planting in areas with high winds or drafts.
They should be protected by some object like a fence, wall, stake, or garden trellis. These plants also will self-seed, so you should avoid planting them near foliage that may be outcompeted.
Keep them at least 2 feet from other plants- including each other! It should also be somewhere that has good circulation. Stale air will lead to fungus. So you don’t want to suffocate it.
You may want to consider planting locations that have enough space to accommodate its height of it. Plants may also need support if they get top-heavy. Plant against a wall or a border where they can get support.
How to grow hollyhocks
Here are some general guidelines on growing and caring for hollyhock.
Care varies depending on the species you’re growing, but these should serve well as general info for getting the most flowers from your plant.
Hollyhock grows well in USDA hardiness zones 2-10. It’s a versatile plant that can grow in a variety of climates. It even tolerates drought when fully grown.
It can handle temperature swings if the roots are well protected. If you’re not in the zone range, you can still grow hollyhock if you provide some mulch to help insulate the roots in the cooler regions.
Hollyhocks prefer fertile, rich soil that’s full of nutrients. They also require well-draining soil as pooling soil will lead to fungal issues or drooping leaves.
The soil should be moisture retaining to help conserve water. When they’re established, they’re drought tolerant. Amend with compost or manure to help increase the nutrient in the soil column for the seedlings to flourish.
Pick sites sheltered from the wind to prevent flopping. The soil must be nice and moist. Beginners often make the mistake of planting it in soil that’s just too dry.
Maintain a soil pH between 6.0-8.0. This is acidic to alkaline. They can tolerate both acidic and basic soils, with the sweet spot being neutral. If your soil is too acidic or basic, you can amend it to fix the levels.
Hollyhocks like acidic soil as it helps encourage blooms. Lime also works well to reduce soil pH.
Plant each seed 0.25 inches deep then cover with light compost. No need to plant the seeds too deep. They do fine near the surface as this helps increase germination rates.
For nursery plants, use a biodegradable pot for transferring to your garden. Plant at the same depth as the original plant.
Space each plant 18-24 inches from each other.
This will provide enough space so they don’t compete for nutrients. Since they have extensive root systems, you need to give them enough room to grow or else they may end up with smaller blooms overall.
Hollyhock will grow well in temperatures that are warmer, but not scorching hot.
They can tolerate some temperature drops to the cold side, but the sudden cold can damage the flowers.
Ideal temperatures should be between 65-70 in the daytime. Excessive heat can lead to scorching, yellowing, or witling. When established, hollyhock can handle temperatures down to 5F!
Hollyhock prefers moderate humidity levels. The soil should be kept moist for younger plants, but established ones can tolerate some dryness in the soil column.
Humidity levels of 50-60% should be the maximum, as it can lead to rust due to moisture content. Reduce humidity if it’s too high by reducing watering frequency. Cut back on dense foliage by pruning it off.
Plant hollyhocks in an area that has full or partial sun. The plant needs between 5 hours of light per day. Morning or evening sun is ideal, as afternoon sun can scorch the foliage.
They like sunlight with plenty of heat, but don’t overdo it. If your plant is leggy, it’s trying to reach for the sun!
Consider getting it into the sunlight. Most hollyhocks do well in partial shade but prefer full sun if it’s not scorching hot. These plants can grow weakly in shady conditions and will flop.
If you’re somewhere that’s hot, dry, or arid, and temperatures hit above 80 degrees Fahrenheit regularly, consider planting in the shade so it doesn’t dry out.
Water regularly on a schedule. The soil should remain moist at all times, but never dry. Don’t let it dry out between waterings if possible. They’re not drought tolerant until they’re established.
Seedlings should be watered 1-2 inches of water per week, depending on your local conditions. Water deeply at the base of the stem. Don’t water the foliage as this encourages fungal issues.
Use moisture-retaining soil to reduce watering. Seedlings will require consistently moist conditions.
Use your finger or a moisture meter to know when to water. The top 5 inches of soil should be moist. But if it’s soggy, that’s not good. That can lead to rust or fungus in the winter.
Once established, watering should be reduced except during hot or dry spells.
These plants can get up to 10 feet or taller. They’ll need some kind of plant support if it’s windy or else they’ll topple over. You can use rope, fences, stakes, or even just your wall.
Hollyhocks will benefit from a light feeding of fertilizer in the spring.
If your soil is nutritious, plant food is not necessary for them to thrive.
But if your soil is lacking, you can supplement it with some soil amendments. Use as directed. Look for an NPK of 10-10-10 or 20-20-20. Basic general purpose plant food products like Miracle Grow will do the job. No need to get fancy.
Use them in the spring before they bloom so you can get more flowers. You can also use compost or manure to help provide nutrients in place of fertilizer.
Fertile conditions are ideal for hollyhock as they need high levels of nutrients in the soil. If your plant turns yellow or has smaller flowers, then the soil may be the culprit.
Amend with organic matter during the spring if your soil is poor. Add food every 2 weeks during the bloom period to help increase size.
Organic fertilizer or fish emulsion high in nitrogen (N) is excellent.
Hollyhock flowers will vary in size and appearance.
The species, local climate, temperature, and how well fed it is determines the number of flowers and how big they are. Most are large (5-6 inches in size).
The blooms are outward-facing with a long stem. Blooms last from early summer to fall. You can encourage more blooms by regulating pruning spent ones.
Ensure that they get enough nutrients- and provide enough moisture content. They make good cut flowers in a vase and can be used decoratively. Hollyhock lasts 10 days when cut.
Use a layer of organic mulch or compost to help increase the nutrient aviaablity in the soil.
You can use up to 5 inches of mulch in the winter to help winterize it. If you’re in zones 5-10, you should be OK for the winter.
No much will be needed unless there’s a temp dip. Hollyhock is hardy to 5F once established.
Hollyhock flowers should be removed after they’re spent. This will help prevent pests or rust from infesting the entire stalk.
You can deadhead it by cutting the entire stalks back to the base of the plant. Don’t let it just sit there. The plant will drop its foliage and start wilting.
Isn’t the point supposed to be growing something pretty to look at?
Note that the plant will die back on its own in the winter. The stems, leaves, and petals will wilt. Cut it back to the soil line to winterize hollyhock. Don’t let it wilt. It’ll bring in rust or pests.
Cutting back after flowering will help encourage another bloom. Mulch with some well-composted manure so it has what it needs for round two. But second blooms aren’t guaranteed. It depends on your growing season.
However, if you want to save the seeds, keep some of the flowers on the stalk. Cut off everything else. We’ll cover how to save seeds later in this care sheet.
Hollyhock requires very little care once established. Just give it plenty of light, water, and plant food. Prune it once a week. Fertilize in the spring to summer. Ensure that it has adequate support.
That’s about all you need to do in terms of care. This plant is excellent for beginners and is very easy to care for flowering perennials. This is why it’s so popular in the cottage gardens.
Winterizing hollyhock depends on where you’re located. If you’re in an area that gets hard freezes, you can only grow hollyhock as an annual rather than a perennial or biennial.
Start seeds indoors then overwinter indoors as well. During winter dormancy, reduce watering and stop fertilizing. Reintroduction to the outdoors in spring when the temperatures warm up.
Deadhead them so you can get exactly how many you want. Propagation is easy with the seeds they produce.
If your zone doesn’t get too cold, then you’ve got it easy. To prepare hollyhock for the winter, cut them down to 5-6 inches.
For cooler zones, use some straw mulch or leaf litter to cover the top 5 inches of the soil line. You can also use organic mulch to do the same over the base of the plant.
Just make sure the root system is insulated from the elements. In the spring, gently remove the coverage 1 inch per week until you acclimate the plant.
When it starts producing again, remove the straw completely.
Growing in containers
Hollyhocks don’t fare well in pots or containers.
They have long roots that need plenty of space to grow outwards. Potted plants also require precise soil metrics (nutrients) and they need more water.
For these reasons, it can be difficult to balance out the proper ideal soil metrics to get your hollyhock to do well in a pot. If you insist on container planting, use a big pot, such as a whisky barrel for the roots to grow.
Dwarf varieties have smaller root systems but still need plenty of space. The container also must be sturdy so it doesn’t topple over.
Remember that this plant doesn’t like to be moved around. Once it establishes itself, it should never be uprooted.
Hollyhock can’t be grown indoors as it’s too big for most households.
It also will need full sun and plenty of room to grow its strong root system. For these reasons, it’s not something you can grow indoors unless you’re germinating seeds.
Saving the seeds for next season is easy. Let some of the flowers fade so they wilt. This will allow the stalks to grow the seeds and then drop them.
Collect the seeds from the soil and clean them with a cotton bud or dry cloth. Put them into an envelope for next season. Keep them out of moisture, light, or high humidity so they remain fertile.
If you want to bring in beneficial pollinators, stick with the single type. If you want that fuller bloom look, then opt for double flowering types.
The majority of hollyhocks will be grown as perennials. You can extend the blooming period by deadheading spent flowers as they fade. If you’re in a nonhumid region, cutting them back to the soil level and then mulching will bring in more blooms.
Hollyhock makes excellent background plants that pair well with shorter perennials in front of it.
There are many plants you can pair with it. Some good choices for plant company include:
- Shasta daisy
- Shrub rose
- Baby’s breath
- Black-eyed Susan
- Sweet William
- Climbing roses
- Rose mallow
- Ornamental grasses
Don’t plant with
You should avoid planting hollyhock with plants that have opposing care requirements.
Don’t plant with taller foliage as the effect of the flowers won’t look as grand. Also, don’t plant with other hollyhocks if they’re less than 2 feet distance from each other.
For the most part, hollyhock is resilient to bugs. It’s also deer resistant, so you can grow it fear-free in your cottage garden if you’re in a rural area.
The most common insects you’ll find on your hollyhock are snails, slugs, spider mites, Japanese beetles, hollyhock weevils, caterpillars, sawflies, aphids, worms, or fleas.
These can leave behind minor visual damage, holes in the leaves/flowers, or yellow spots on the leaf surfaces. Orange or brown raised pustules on the lower leaves can be caused by Puccinia malvacearum is a rust fungus, not a pest.
Horticultural oil, pyrethrin, carbaryl, acephate, soaps, or commercial products can be used to eliminate these pests.
Most of them can be ridden by simply removing them manually. Use a high pressure hose to spray them off as you water.
If you need to use insecticides, consider using organic ones instead of synthetic ones.
This is better for your garden, especially if you have edibles, pets, kids, etc. It’s also good for the planet. Snails and slugs can be baited with beer traps or removed by hand.
Spider mites can be ridden with diatomaceous earth. Beetles can be ridden with neem oil. No need to use poisonous compounds that harm your hollyhock!
Rust is a common problem with hollyhocks. Rust looks like small yellow spots on the leaves. It turns brown over time. The rust can show up on the bottom of the foliage.
It can be controlled by watering at the base, minimizing watering, and pruning regularly. If your plant is dense, it restricts evaporation. This leads to fungal issues.
So you wanna make sure you never overwater, overfeed, or fall back on pruning. Keep your hollyhock nice and clean. Fungus loves environments with poor water drainage or high moisture foliage.
Hollyhock is versatile in the sense that you can use them for a variety of purposes.
Use them as the backdrop of your cottage garden outlining the perimeter with its towering flowers. It can also be planted with other perennials like roses, dahlias, or bellflowers for endless blooms every season.
Many people line their fencing or other structures with this plant because it grows tall. You can use it to hide vertical structures like your house exterior, sheds, or fencing if you want to hide those uglies.
Other common questions about hollyhock care
Here are some questions from readers about general care for hollyhocks. Note that YMMV. It depends on what type of hollyhock you’re growing and where you’re located.
You may find these tips helpful. If you have questions of your own, please leave a comment at the end of this care guide!
How long does it take hollyhocks to grow?
It takes about 2-3 weeks for seeds to germinate.
From there, it’ll take 2 years for a hollyhock to establish itself and then produce flowers. Some will bloom within 1 year, but this depends on the variety.
What month do you plant hollyhock seeds?
Hollyhocks should be planted in seed beds in the late summer.
They can be sown indoors or outside in containers. This is usually in March through May if sown under covers. Once planted, don’t disturb the seeds.
How many years do hollyhocks last?
Hollyhocks are perennials when grown in ideal conditions. They’ll self-seed to produce more plants as soon as they fade. They last 2-3 years.
Do hollyhocks survive winter?
Yes, hollyhocks will survive the winter. They’re hardy down to 5F when established. If it’s especially cold in your zone, keep the entire root system using organic mulch. 4-5 inches is enough to help keep it warm during the cold snaps.
Are hollyhock roots invasive?
Hollyhock is considered an invasive plant in the US.
It’s contributed to 42% of US threatened/endangered species. This is why self-seeding plants can be dangerous.
Be sure to remove seedlings next season that you don’t want to keep. The roots are also extensive and will take over nearby plants. Provide ample room from nearby foliage so they don’t compete.
Why are the flowers falling off my hollyhock?
There can be many reasons. Flowers drop in extreme heat or extreme cold. Temperature fluctuations can also lead to blossoms falling off.
Too much shade or too much light can also cause leaf drops.
Wind, rain, or other natural weather patterns can harm your plant. If it’s too tall and sways in the wind, this can force the blossoms to fall. Provide adequate light and nutrients in the soil.
Do birds eat hollyhock seeds?
Birds do indeed eat the seeds. Hollyhock brings in pollinators like bees and birds. Both of which will flock to the flowers. If you have plants that need pollinating, hollyhock can help.
What can I do with hollyhock seeds?
Hollyhock seeds can be saved for next season. Snap the seed pods off the stalks with your fingers then store them in a sealed container.
That’s all there is to harvest them. They’ll be good until next season.
Do hollyhocks bloom the first year?
Hollyhocks will generally bloom in the second year rather than the first. This is why they’re known as biennials.
Some species will bloom the first year if planted early enough, such as the queeny purple variety.
But most species will need a dual season to bloom.
Check out these sites for more info on hollyhocks:
- Growing Hollyhocks – SDSU Extension
- Explore Cornell – Home Gardening – Flower Growing Guides
- Common Hollyhock (Alcae rosea) – UIC Heritage Garden
- Hollyhock Rust – Wisconsin Horticulture
Hollyhocks take care of themselves
Once you get them going, you don’t need to do anything else. Hollyhock is one of those perennials that just don’t need to worry about other than basic TLC.
These plants make excellent background plants with their towering nature.
With a variety of easy blooms, colors, and tolerance to drought, hollyhock is a garden favorite.
Do you have questions about growing and caring for hollyhock? Post them!
I’ve always been interested in gardening, but I never took it seriously until I was forcefully gifted an orchid. This was what got me into the hobby and I’ve never looked back. I enjoy writing about it, but not nearly as much as getting into the dirt and sculpting the perfect decorative ornamental to enjoy for the times.