A classic cottage garden staple, hollyhocks (Alcea rosea) bloom mid-summer with numerous flowers on tall spikes. 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. In the second year, the stalks shoot up, flowers bloom and seeds form. However, there are also many varieties that behave like short-lived perennials and will flower in their first year when planted early enough in spring or started indoors in winter.

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.

On this page: Basics | Planting | Care | Varieties | Gardening with Hollyhocks

On this page:

• BASICS
• HOW TO PLANT HOLLYHOCKS
• HOLLYHOCK CARE
• HOLLYHOCK VARIETIES
• GARDENING WITH HOLLYHOCKS

HOLLYHOCK BASICS

Zones:

3-9

Height/Spread:

6-8 feet tall, 1-2 feet wide

Exposure:

Full sun to part shade

Bloom time:

June-August

Color and characteristics:

The single or double, cup-shaped flowers have little or no stalk and bloom on tall spikes. 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.

Are hollyhocks poisonous?

Hollyhocks aren’t noted as being poisonous when ingested. However, the stems and leaves can cause skin irritation when the small glass-like fibers on them are touched or brushed against.

Are hollyhocks deer resistant?

Hollyhocks are seldom browsed by deer.

HOW TO PLANT HOLLYHOCKS

How and when to plant hollyhock seeds:

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.

Where to plant:

Plant in a well-draining area with full sun to partial shade. Due to their height, protect from damaging winds and provide support such as a fence, wall, trellis or stake. Hollyhocks will readily self-seed if left to their own devices, so locate them in an area where this won’t be a nuisance. Also, hollyhocks are one of very few plants that can be planted in proximity to black walnut trees because they are tolerant of the chemical juglone that is leached into the soil by the tree.

HOLLYHOCK CARE

Pruning:

Individual hollyhock flowers can be removed when they fade and entire stalks can be cut back to the base after flowering. This will prevent seed heads from forming and reseeding. Although, if you’d like to have seeds set for next spring, leave the flowers and a few stalks until the seeds have dropped. They’ll die back in winter and all stems and leaves should be cut back to the ground to prevent rust disease from overwintering.

Soil:

Provide rich, moist, well-drained soil for hollyhocks.

Amendments and fertilizer:

Hollyhocks can benefit from a light application of fertilizer or compost in the spring.

Watering:

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.

Propagation:

Hollyhocks are best, and easiest, grown from seed and they will readily self-seed if flower stalks are left in place.

Diseases and pests:

They are prone to hollyhock rust, a fungal infection that first shows as yellow spots on leaves, then develops into brown or rust colored bumps on the underside of the leaves. Preventing rust is much easier than trying to tame an outbreak. Watering from below, good air circulation and thorough late fall cleanup will go a long way in stopping rust from forming. Any leaves that show signs of rust should be removed from the plant and disposed of to prevent further spread. There are cultivars that have been developed to be more rust resistant, such as Alcea rugosa varieties.

Slugs and snails, spider mites and Japanese beetles can be problematic as well.

Over-wintering:

In areas that get hard freezes, hollyhocks can be grown as annuals, starting seeds in containers and over-wintering indoors. Water sparingly over the winter and gradually reintroduce them outside when the weather begins to warm up.

In other areas where they can be left outside, prune them back to about 6 inches above ground level in the fall. Cover with 4 to 6 inches of straw or mulch over the root zone and base of the plant. In spring, gradually remove in layers to slowly acclimate the roots. Once new growth is emerging, remove all the straw or mulch. Re-cover in case of a spring freeze.

HOLLYHOCK PICTURES

GARDENING WITH HOLLYHOCKS

• Hollyhocks add drama and height, making an impressive backdrop to shorter perennials.
• Attract hummingbirds and butterflies to your garden.
• Plant with companions such as dahlia, clematis, Shasta daisy, shrub rose, baby’s breath, black-eyed Susan, phlox, sweet William and climbing roses.
• Include denser plants in front of them to hide their sometimes unattractive legs.
• Hollyhocks can be tricky to transplant due to their long taproots, so locate them accordingly so they won’t have to be moved.

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