You might have noticed red, white, and pink hollyhocks growing alongside centuries-old barns, outside country stores, and planted throughout classic cottage gardens. They have an old-timey aura that makes me feel like a kid again.
Hollyhocks come in a variety of bold and bright colors ranging from white to blue to nearly black. They’re herbaceous flowering plants that are considered biennials or short-lived perennials. Hollyhocks are related to cotton and hibiscus, and they are native to China. If you’re looking for an easy-to-grow plant that will provide classic beauty for several years, look no further.
Let’s get into how to easily start hollyhocks from seed so you can add them to your garden this season.
Gather Supplies
Growing hollyhocks from seeds requires hollyhock seeds, cell trays or pots, and seed-starting mix.
Supplies needed:
- Hollyhock seeds
- Cell trays if starting indoors
- Optional heat mat
- Seed-starting mix
- Access to water
- Labels
- Light: natural or artificial
Sowing Seeds Indoors in the Spring
Start hollyhock seeds indoors in biodegradable pots to prevent transplant shock.
Hollyhocks produce a long, strong taproot, so when seeds are started indoors, we recommend using biodegradable pots. Transplanting these directly into the ground will decrease the risk of transplant shock.
Sow seeds indoors eight to ten weeks before the last spring frost in March, April, or May, depending on your growing zone. Just barely cover the seeds as light aids in germination and bottom water to keep them from being displaced.
Use a heat mat to maintain a temperature of 60-70°F (16-21°C) during the germination period, which takes 10-14 days. Provide light once you notice sprouting.
Sowing Seeds Indoors in the Summer or Fall
Seedlings should be stepped up into a 3-inch pot to promote healthy growth before transplanting.
Growers may try to cheat the natural biennial system by sowing seeds in a protected area in late summer or fall in hopes of blooms within 12 months. Depending on your growing conditions and zone, this may work! Otherwise, there are a few varieties thought to bloom in the first year.
Start them the same way as indicated above. Step seedlings up into at least a 3-inch pot to help them establish healthy growth before being transplanted out in the spring.
Sowing Seeds Outdoors
For improved hollyhock germination rates, plant in May-July or during fall.
Sow seeds directly outside in May, June, or July in the area you’d like them to remain, as they don’t transplant well once a strong taproot has formed.
Alternatively, sow them in the fall when temperatures have cooled, allowing them to go through a natural cold stratification period, which may increase germination rates.
Growing On
Properly hydrate hollyhock seedlings from below and ensure adequate airflow for optimal growth.
Keep the seedlings moist as they grow for several weeks indoors or in a greenhouse. Water from below by placing pots or seed trays in a shallow tray containing water. Allow them to uptake water from the tray and remove it once you can see moisture on the soil surface. Do not leave the seedlings sitting in still water.
Temperatures should be mild, and fans will provide healthy airflow.
Hardening Off
Gradually acclimate seedlings outdoors over ten days to avoid transplant shock post-spring frost.
Seedlings should be ready to get acclimated to the outdoor elements about three weeks after the last spring frost. Slowly increase their time spent outside for ten days until they have spent a few full days in direct sunlight, received precipitation, and spent the night outside. This prevents transplant shock.
Transplanting and Spacing
It’s time to transplant seedlings with two sets of true leaves after three weeks post-last spring frost.
Plant out your seedlings when they have at least two sets of true leaves and at least three weeks have passed since your last spring frost. Space them at 12-18 inches, and don’t overcrowd your garden. Keep in mind their ability to self-seed.
At the end of its first year, you’ll likely have lots of lush, dark green foliage and a deep underground root system but no flowers.
The following year is when you’ll get to enjoy its tall, showy stems and colorful blooms. They’ll flower, go to seed, and possibly perish, leaving behind seeds for the next generation.
Soil and Sun Requirements
These plants thrive in well-draining soil and full sun.
Hollyhocks require well-draining soil in an area that receives full sun.
Pro tip: Hollyhocks are one of few plants that can tolerate the chemical juglone put out by black walnut trees that sometimes affects the growth of root and stem systems.
Offering Support
The plants typically reach five to eight feet in height and benefit from staking for support.
Hollyhocks grow to five to eight feet tall, with some new varieties bred to be a bit shorter at four to five feet. Due to their height, they work best along a fence line, against a building, or at the back of a perennial garden bed.
Stake your plants if you don’t have a structure that can offer natural support to avoid them being blown over in the wind. Dwarf varieties do not require staking or support.
Water Requirements
Hollyhocks require consistent moisture during germination and growth, transitioning to drought tolerance once established.
Keep the soil moist as they’re germinating and growing on as well as newly transplanted. Avoid overhead watering to decrease the risk of fungal diseases. Once established, hollyhocks are drought-tolerant, but regular watering should be provided.
Fertilizing
Feed hollyhocks with compost or liquid fertilizer in spring for prolonged blooms.
Apply compost at the time of transplant or when new growth emerges in the spring. Feed using a liquid fertilizer when growth starts to really take off and repeat a few weeks later. Regular fertilization will increase the bloom time. Cease any feeding once they begin to flower.
Mulching
Protect emerging spring seedlings from frosts and reduce rust spore infection risk with mulch.
Mulching protects young spring seedlings from frosts as they start to emerge and decreases the risk of rust spores from infecting them.
Successive Sowing
Hollyhocks self-seed easily and can bloom the following year if sown outdoors in the fall.
Hollyhocks are a short-lived perennial, some living for just two to three years. However, if you place them in an area where they can freely self-seed, they’ll start new seedlings for you without much effort from you. Keep this in mind when selecting its place in the garden.
Direct sown seeds outside in the fall may get you blooms the following year.
Pruning
Prune stems after flowering to prevent self-seeding or sow new seeds annually for a continuous supply.
Stems can be cut back to the ground after flowering, which will prevent them from self-seeding. Leaving spent foliage in place will offer protection to new foliage at the plant base level.
If you prefer the clean look of pruning and deadheading, sow new seeds each year to guarantee a continuous supply from the previous year’s planting.
Harvest
Sear hollyhock stems with a flame for 20 seconds before adding them to water.
Hollyhocks make incredible cut flowers for their height. A sap will ooze out when the stem is cut. Wait until the sap stops flowing before adding cut stems to fresh water or sear the end with a flame for 20 seconds.
Trim off the bottom inch on an angle every few days following the same process as above. Change the water at this time.
Collecting Seeds to Save
To prevent germination, dry seed pods thoroughly and store in an airtight container until spring.
As I mentioned earlier, hollyhocks will easily self-seed, but if you don’t want the seeds to germinate, simply remove the pods in late fall once the seeds inside have transitioned from white to black.
If there is any moisture remaining in the pods, break them open and allow them to fully dry in a dry place to avoid mold developing. Once they’re fully dried, store them in an airtight container or brown seed bag until the spring.
Winterizing in Year One
Protect first-year hollyhock plants in winter by cutting back to six inches.
Shelter your first-year hollyhock plant by cutting back to six inches and removing any spent foliage and debris. A heavy mulch of organic straw, leaves, or compost offers protection in areas where winters are harsh.
In the spring, after the risk of frost has passed, pull back the mulch so sprouts can breathe and receive sunlight. Leave the mulch around the base of the plant to provide fertility to the soil as it breaks down.
If your hollyhocks are still growing in containers, simply bring them inside until temperatures are agreeable.
Popular Varieties
The classic look of bright pink and yellow hollyhocks and towering spikes is making a comeback, but if you need something a little shorter, try a dwarf variety.
‘Chater’s Double’
The ‘Chater’s Double’ hollyhock was developed in the 1880s by English horticulturist Chater of Essex.
Named for English horticulturist Chater of Essex, this popular hollyhock heirloom was developed in the 1880s. ‘Chater’s Double’ is coveted for its fluffy double two to four-inch white, pink, golden yellow, and magenta blooms and long bloom time.
Plants can reach five to eight feet tall and are hardy in zones 2-8.
‘Indian Spring’
A perennial flowering plant, ‘Indian Spring’ grows up to 5-8 feet in rich soil.
This classic variety won the All-America Selections award in 1939 and is still adding charm to backyard gardens today. Blooms are two to four inches tall and come in white, pink, rose, and yellow shades.
‘Indian Spring’ is known for flowering in its first year and does best with moist, rich soil. Plants reach 5-8 feet tall.
‘Outhouse’
A hardy plant named ‘Outhouse’ thrives in rich soil and ample water.
Can you believe these gorgeous blooms used to hide outhouses from view? Their six to nine-foot height lent themselves well to hiding small buildings, but today, they adorn the outside of barns, garages, and garden sheds and make great garden borders along fence lines.
‘Outhouse’ is a blend of two-inch white, soft and bright pink, and red, some boasting contrasting centers. Plants perform best when the soil is rich, and they receive ample water. This variety is hardy in zones 3-9.
‘The Watchman’
Hardy in zones 2-8, ‘The Watchman’ cultivar complements goth gardens with its moody vibes.
This seductive variety is deep and rich burgundy that makes bright pinks and yellows pop when added to the back row of a perennial garden. Plants reach 5-7 feet.
Blooms are two to four inches and make a great garnish. Although the flowers are edible, their flavor is bland, and centers may be bitter, so they’re best if used as eye candy.
‘The Watchman’ is hardy in zones 2-8. Its moody vibes would work well in a goth garden.
‘Creme de Cassis’
A striking first-year bloomer, ‘Creme de Cassis’ thrives in zones 3-9.
This gorgeous first-year bloomer features white blooms with a wine-colored center with outstretching veins, making it an interesting choice for sure. Plants can reach six to eight feet tall and perform best in zones 3-9.
Plant ‘Creme de Cassis’ along the back edge of a cottage garden or use them to disguise an unsightly garden shed.
Queeny Mix
At two feet tall, ‘Queeny Mix’ hollyhocks suit small gardens, ideal for containers.
This variety tops out at two feet tall, offering the classic look of hollyhocks in a more practical size for small-space gardeners. ‘Queeny Mix’ can be grown in raised beds or containers and can be dried to be used in everlasting bouquets.
Final Thoughts
Hollyhocks will add an old-timey feel to any garden, available in various colors and petal sizes, and will provide you with free plants every year if you allow them to self-seed. Their height makes them an easy choice for the back edge of a cutting, cottage, or pollinator garden.
