When Can You Plant Hollyhocks?

Hollyhocks produce multiple flowers along tall stalks.

Hollyhocks grow as biennial flowers, which means it takes them 2 years before they begin blooming and complete their life cycle. You can control how quickly they flower by carefully choosing the planting time for the flowers. By planting late the first year, you can get flowers as quickly as the following summer, effectively tricking the hollyhock into flowering in one year instead of two.

Winter Indoor Planting

Hollyhock seeds take approximately three weeks to germinate when a temperature of 60 degrees F is maintained. Starting the seeds indoors in midwinter produces transplants that are ready to bloom the first summer after planting. Seeds planted in winter will grow in their pot for approximately three months. Use a 5-inch-diameter biodegradable pot so you can transplant the hollyhocks to the garden without damaging the plant's taproot.

Indoor Spring Planting

Seedlings planted indoors in mid-spring may not flower until the second year after planting. Start spring seeds approximately five to six weeks before the last expected spring frost. Use small, 2- to 3-inch-diameter biodegradable pots, as spring-started hollyhocks are transplanted out to the garden while they are still small, unlike winter-planted seeds.

Summer Planting

Plant indoor-started seedlings or purchased bedding plants in early summer once all frost danger is passed. You can also sow seed directly in the garden bed once the soil has warmed up to 60 degrees F. Seeds sown outdoors in early summer usually don't bloom until the second year, though the plants will produce healthy vegetative growth the first summer. Plant the seeds no deeper than 1/8 inch and keep the garden bed moist at all times to ensure even germination.

Fall Planting

Fall planted hollyhock seeds flower the following summer. Plant the seeds directly in the garden bed in August so the seeds have a chance to germinate and establish a healthy root system in the garden before the first frost in late fall. Mulch over the hollyhock bed once the ground begins to freeze if you sow your seeds in fall. The mulch provides insulation and protects the young plants from winter cold.

References

• University of Illinois Extension: Hollyhocks: A Favorite Summer Flower ; Sandra Mason; July 1998
• Michigan State University: Alcea rosea: Hollyhock