Growth of Hollyhocks

Growth Habit

• Hollyhocks belong in the Malvaceae family. They are a relative to hibiscus, cotton and okra. Gardeners have many selections in varieties of hollyhocks, with over 60 species in the genus Alcea, according to the New Mexico State University extension service. Depending on the variety, the plant performs as an annual, semi-annual or biennial. Biennial plants require two seasons to complete their cycle of growth. Hollyhocks that are biennial and grown from seed spend the first season developing a root system and foliage. In the second season, the plant blooms and produces fruits. Transplants grown in the garden sometimes flower in the first season, as do annuals.

Plant Description

• Depending on the cultivar, hollyhock plants grow anywhere from 5 to over 8 feet tall. The plant produces a tall and erect center stalk covered in hairs. The 2-inch green leaves cover the stalk and feel like sandpaper. The flowers fill the stalk springtime throughout summer. Blooms range in size from 2 to 4 inches and are funnel shaped. The blooms are single or double. Flower colors include brown-maroon, white, yellow, pink, purple, scarlet and salmon. After the flowers fade, seedpods form. When the seedpods become brown and dry, gardeners can harvest the seeds for planting the following season. Hollyhock seeds are flat, coinlike and approximately a half-inch in diameter.

Growth Requirements

• Select an area in the garden for planting the hollyhocks that is located in full sun and protected from strong winds. Due to the plant’s tall habit, staking is sometimes required. Choose an area that is weed-free and has soil that drains well. Amend the planting site with a 6-inch layer of manure or compost. If planting transplants, space the plants approximately 18 inches apart. Plant the transplants at the depth the plant was growing in its container. If planting hollyhock seeds, cover the seed with a light dusting of soil. For a formal look, space the seed 18 inches apart. Plant the hollyhock transplants and seeds during springtime.

Care

• Hollyhocks are drought-tolerant and durable plants. During hot weather, saturate the soil regularly with water. Apply the water to the ground and not on the plant’s foliage. The plant is susceptible to hollyhock rust (Puccinia malvacearum) and powdery mildew. Overhead watering makes the plant more susceptible. The rust fungus covers the foliage in small brown, yellow or orange spots. Powdery mildew leaves a white substance on the foliage. In severe cases of infestation, the leaves will die. Gardeners should spray infected plants regularly with a fungicide. Prune the plants down to the ground after blooming. Discard infected foliage in a plastic bag and do not compost. Apply an all-purpose fertilizer two to three times during the growing season. Follow label directions concerning applying the fungicide and fertilizer.