This cottage garden classic originated in China, but was imported to English gardens around the 15th century. Hollyhocks defy the simple definition of annual, biennial, and perennial depending on when, where, and how they are planted. Technically, this species is a short lived perennial. If started early enough indoors, it will flower the first year and can be treated as an annual. Planted later in spring, it will bloom in the second year as a traditional biennial. Continue reading below for tips on how to grow hollyhocks from seed.
Season & Zone
Exposure: Full sun to partial shade
Zone: Hardy to Zone 5
Start hollyhocks 6-8 weeks before planting out after the last frost date. In mild winter areas, start seeds indoors in late February to early March, and transplant out in April or May. An early start usually results in flowering the first year. Seeds germinate in 10-14 days. Ideal soil temperature for germination: 15-21°C (60-70°F).
Sow seeds on the surface of the soil, and provide bright light. Use peat or coir pots in an effort to minimize root disturbance. Transplant at 45-60cm (18-36″) apart.
Grow in rich, moist soil with good drainage and a neutral pH range of 6.0-7.5. The most important factor is good air circulation, so do not crowd plants or plant too close to structures, hedges, etc… Keep well watered and feed a few times during the growing season. If the flower stalk is cut back immediately after finishing, plants may bloom again. Stake tall plants.
Rust is a leaf disease to which hollyhocks are especially prone. It is worse on older plants and can be kept in check by replacing plants every couple of years.