However, they dislike this and prefer it when they are sown directly outdoors. Growing hollyhocks in the sunny garden makes a statement. How to Grow Hollyhocks. Hollyhocks grow 6 to 9 feet tall and make a colorful backdrop for smaller plants and shrubs. Here are some of the most asked questions about hollyhocks: No, hollyhocks are not poisonous. If the petals are discolored and the flowers are not about to die, this may be a case of powdery mildew. Hollyhocks do not need fertilizers, but they do need mulch! You can also harvest seeds from plants in the fall. Nothing you can do right now while it is hot, but in the fall and winter, amend the soil heavily so your hollyhocks will grow tall and strong next year. Hollyhocks from the Spotlight Series collection grow to a height of 59 to 70 inches tall and grow in USDA zones 3 through 9. You can try an organic fertilizer or remedy to cure them. At first we thought they were all yellow, but they ended up to be mixed; pink, white, light yellow and the star of them all … Plant hollyhocks at the correct time. Providing tall spikes of large summer blooms, hollyhocks (Alcea rosea) grow best from seed sown outdoors in their final growing sites. If you live in an area where there are long periods of drought, then it is advisable to water them every other day, depending on their location. Hollyhocks’ seedlings can be transplanted outdoors if they have grown indoors. Varieties include “Spring Celebrities Purple,” “Spring Celebrities Lilac” and “Spring Celebrities Crimson,” which all have blossoms whose colors match their names. As a biennial flower, Hollyhocks are known for investing all their energy into growing successfully and strongly during their first year of life. Hollyhock heaven: Alan Titchmarsh on growing hollyhocks NO TRADITIONAL cottage garden would be complete without the tall, graceful spires of hollyhocks. Weinblatt received her B.S. Plant in rich, well draining soil. It has purple-black flowers with contrasting maroon centers. A tall, stately plant, hollyhocks are prone to wind damage. Alcea rosea “Nigra” is an unusual and historic selection known as black hollyhock. Hollyhocks are the quintessential cottage garden flower. In addition, hollyhocks are good for the garden and the environment, as they also welcome many pollinators that need the flower’s nectar to survive. They come in a variety of colors, including “Peaches and Dreams” with flowers in peachy-pink. Hollyhocks, Alcea, have long been associated with cottage gardens. They look best up against a wall or at the back of a … Hollyhock plants can get up to 10 feet tall and when the flowers are blooming near the top they get top heavy and can topple over. They do have some specific requirements, but if the right growing conditions are met, these flowers will reseed themselves for years to come! Victoria Weinblatt began writing articles in 2007, contributing to The Huffington Post and other websites. Known for their large, showy flowers, these perennials prefer full sun and require soil with average moisture. You can also strategically place hollyhocks to create shade that keeps walkways cool or protects sensitive plants from afternoon sun. They are very romantic as well and will look great if placed at the back, behind other colorful and shorter flowers. Be sure to transplant hollyhock plants into fertile, well-composted soil in a sunny location. Hollyhocks need moist soil. They can be directly grown outdoors, a week or two before the last frost of the region, or you can start some seedlings at least three weeks before the last frost.