How to Grow Hollyhocks: Planting and Care Tips

Hollyhocks are one of those flowers that make a garden feel established. The tall flower stalks can reach several feet high, and once they start blooming, the flowers open from the bottom up over several weeks.

In the low desert, timing and placement make a big difference. Hollyhocks do best when planted during the cool season so they have time to develop before summer heat arrives. Give them morning sun, good airflow, and enough room, and they can put on an impressive spring display.

Many hollyhocks are biennials, but they reseed so readily that they often seem like perennials. Here’s what to know about planting, growing, managing rust, and keeping hollyhocks coming back.

Understanding Hollyhocks: Biennial or Perennial?

Many hollyhocks are biennials, although some varieties bloom the first year.

A biennial hollyhock usually spends its first season developing roots and a rosette of leaves. The second year, it sends up tall flower stalks, produces seeds, and then finishes its life cycle.

That can make hollyhocks confusing because they often seem perennial in the garden. They reseed easily, and new seedlings can appear around established plants year after year.

For biennial types:

• First year: Roots and foliage develop.
• Second year: Flower stalks form, bloom, produce seed, and then die back.

Tip: If you want hollyhocks to keep returning, allow some seed pods to mature and drop naturally. These self-sown seedlings can help make hollyhocks a permanent feature in your garden.

Ideal Growing Conditions for Hollyhocks

Hollyhocks grow best in well-drained soil with plenty of organic matter and good airflow around the plants.

Plant seeds about ¼ inch (6 mm) deep. Space plants around 2 feet (60 cm) apart so air can move between them, which also helps reduce rust problems. I get these hollyhock seeds from Botanical Interests.

Water deeply enough to encourage a strong root system, then allow the upper part of the soil to begin drying before watering again. Avoid constantly wet soil and, when possible, water at the soil level rather than wetting the leaves.

In mild climates, full sun works well. In the low desert and other hot-summer climates, morning sun with afternoon shade is a better choice.

When to Plant Hollyhocks in Different Climates

Low Desert of Arizona

• Start seeds indoors: August through January
• Plant seeds or transplants outside: October through March

Earlier planting usually gives the plants more time to establish before spring flowering and can result in taller flower stalks.

Cooler Climates

Start seeds indoors about 8 to 10 weeks before your last frost, or direct sow when the soil can be worked. Transplant outside after the danger of hard freezes has passed.

Mild-Winter Climates

Fall is often an excellent time to plant hollyhocks. Cool weather gives the plants time to establish roots before spring flowering.

Using Hollyhocks in the Garden

Because hollyhocks can grow several feet tall, plant them toward the back of a border or where their height won’t shade shorter plants.

Their tall flower stalks work well with roses, larkspur, dianthus, bachelor’s buttons, and other cottage-garden flowers.

Hollyhocks also attract hummingbirds, butterflies, bees, and other pollinators. As members of the mallow family, they can also serve as host plants for some caterpillars. See the Arizona Butterfly Garden Guide to round them out with nectar, milkweeds, and a simple puddling station.

Flowers may be single or double and come in shades of white, yellow, pink, red, peach, and nearly black. Choose varieties based on the desired height and flower form for your garden.

How to Encourage More Blooms

Hollyhocks don’t need much once they’re established.

Top-dress with compost before the growing season if your soil needs it, and remove damaged or diseased leaves as they appear.

Deadheading spent flowers can encourage the plant to keep blooming instead of putting energy into seed production. If you want hollyhocks to reseed, don’t deadhead every stalk. Leave some flowers in place and allow the seed pods to mature.

Bloom time depends on climate. In the low desert, hollyhocks usually bloom from spring into early summer.

Preventing and Managing Rust on Hollyhocks

Rust is one of the most common problems with hollyhocks. You may notice yellow or orange spots on the leaves, followed by rusty-colored bumps on the undersides.

A few things can help reduce problems:

• Give plants enough space. About 2 feet (60 cm) between plants improves airflow.
• Water at soil level. Avoid repeatedly wetting the leaves.
• Remove affected foliage. Cut off badly infected leaves and discard them rather than adding them to your compost pile.
• Clean up around plants. Remove old leaves and plant debris where spores may remain.
• Start with healthy plants and soil. Strong plants usually handle some damage better than stressed plants.

If rust becomes severe, remove heavily infected plants. I prefer to focus on prevention and sanitation before turning to sprays.

What to Do After Hollyhocks Flower

What you do after flowering depends on whether you want more hollyhocks.

If you want them to reseed, leave some flower stalks in place. Allow seeds to fall naturally, or collect them to plant elsewhere. To save seeds, wait until the seed pods are completely dry and brown, then collect them for sharing or planting in other parts of the garden. See my seed-saving guide here.

Once seed collection is finished, cut spent flower stalks back near the base. If the plant still has healthy basal foliage, leave that in place.

Biennial plants may finish their life cycle after flowering and seed production. That’s normal. The seedlings around them are what keep the planting going from year to year.

Self-sown hollyhocks may not look exactly like the parent plant, especially if several varieties are growing nearby.

How to Grow Hollyhocks in Arizona

Hollyhocks grow well in Arizona’s low desert when they’re planted early enough and given some protection from the hottest afternoon sun.

Plant at the Right Time

Start seeds indoors from August through January and plant seeds or transplants outside from October through March.

Earlier planting gives plants more time to develop roots and foliage before spring temperatures rise. Plants started earlier in the window often produce taller flower stalks.

Choose the Right Location

Morning sun with afternoon shade is ideal. Hollyhocks can also do well in bright filtered light.

Avoid planting them against hot west-facing walls where reflected afternoon heat can shorten their season. North- or east-facing exposures are often better choices. To find plants that can handle the heat, try this list of the best plants for reflected heat.

Expect Spring Blooms

In the low desert, hollyhocks typically bloom from April through June, with some continuing into July depending on the weather and location.

After Blooming

Allow some stalks to form seed if you want plants to reseed. Once the seeds have matured, cut spent stalks back and remove old or diseased foliage.

Fall is a good time to move small self-sown plants while temperatures are cooler.

Hollyhocks may not look like long-lived perennials here, but if they’re happy and allowed to reseed, they can return year after year.