How To Grow Hollyhocks: Expert Tips For Summer Stunners

How To Grow Hollyhocks For Stunning Summer Blooms

Hollyhocks are a quintessential part of any cottage garden. Grown as a biennial, hollyhock plants are a favorite of pollinators and even serve as a host to painted lady butterflies. Though established beds require relatively little care, learning when and how to start the plant will be key to success. How do you grow hollyhocks?

QUICK FACTS

Botanical name: Alcea rosea

Height: 3-6 ft. (1-1.8 m.)

Spread: 12-24 in. (30-60 cm.)

Sun exposure: Full Sun

Soil requirements: Well-Draining

Hardiness zones: USDA Zones 3-8

When to plant: Spring, Mid-Summer

Caring for Hollyhocks

Lighting Conditions

To look their best, hollyhocks need plenty of direct sun. This means planting them into beds that receive at least 6-8 hours each day. Though they can tolerate some shade, excess shade may cause the plant to stretch or become leggy. Flowering can also be affected, resulting in the production of fewer or smaller blooms.

Temperature & Humidity

Hollyhocks perform well under a wide range of conditions. However, temperatures that are especially cool or hot may slow their growth and can affect their overall performance. Though hollyhocks can be grown in regions that experience high humidity, they may experience an increased susceptibility to disease.

Watering Needs

Routine watering through the summer helps to maintain consistent moisture in hollyhock beds. The plants should be watered from below, making certain to avoid the accidental wetting of leaves. This method, most often achieved through the use of drip irrigation or soaker hoses, helps to prevent common diseases.

Best Fertilizing

Hollyhocks are heavy feeders. This means that they benefit greatly from routine fertilization. Feed the plants every 6-8 weeks with a well-balanced, slow-release fertilizer that has been specifically formulated for use with ornamental plants.

Soil & Compost

Hollyhocks require a rich, fertile soil. Add some finished compost and other amendments at planting time. Provided their nutrient needs have been met, hollyhock plants are highly adaptable and can tolerate a wide range of soil types, including those that are alkaline or acidic.

How to Grow Hollyhocks From Seed

Before we can learn how to plant hollyhock seedlings, we’ll first need a better understanding of the plant’s needs for germination. Hollyhock seeds germinate readily and are planted in either spring or summer. Soaking seeds in warm water may help to speed germination, but it is not required. Seeds can be started indoors, in trays, but most find sowing directly into prepared beds to be the best option. You can expect hollyhock seeds to begin growing approximately 1-2 weeks from planting.

Hollyhock Support & Pruning

Hollyhocks have a long bloom period, with flowers slowly opening across each stem. Flowers can be pinched from the stem as each one fades. This helps prevent the production of seed and helps to keep the plants looking tidy. Another key component of learning how to plant hollyhocks is support. Often, tall plants will begin to bend or lean due to the weight of flowers or weather conditions. Hollyhocks can be trellised in a variety of ways, including the use of individual stakes, cages, and/or netting.

Problems, Pests & Diseases

Though beautiful, hollyhocks are affected by a wide range of diseases. Most notable among these are powdery mildew and rust. Both result from issues related to moisture and humidity. This makes using proper watering techniques and spacing vital to their prevention. Several nuisance pests like to frequent hollyhock plants. Hollyhock weevils, specifically, feed on all parts of the plant. Japanese beetles can also be a problem, causing extensive damage to flowers and foliage.

How to Propagate Hollyhocks

Hollyhocks are best propagated by seed. The process begins when flowers are pollinated. After several weeks, the seed pods will have started to dry. Mature seeds can be harvested from the plant at this time, but be certain to do so before the pod splits open. Once open, pods can drop large numbers of seeds into garden soil. This makes the hollyhock an ideal addition to self-seeding or low-maintenance flower beds.

Frequently Asked Questions

Do Hollyhocks Come Back Every Year?

Most hollyhocks are biennial. This means that they will produce foliage in their first season, returning only to bloom and set seed in their second. Some newer varieties will flower in their first year, behaving as an annual. Therefore, sowing new seed into the garden each season is required.

How Tall Do Hollyhocks Get?

Though there are some varieties of dwarf hollyhock, most grow to be relatively tall. You can expect dwarf plants to reach approximately 12-36 in. (61-91 cm) at maturity, with more traditional types growing to around 3-6 ft. (1.0-1.8 m) in height.