Old-fashioned hollyhocks (Alcea rosea) never fail to command attention, with towering spires of blooms in a rainbow of shades, including pink, red, white, yellow and purple. Sturdy plants that demand little attention, hollyhocks are old-fashioned summer bloomers. Often considered to be perennial plants, hollyhocks are actually biennial, meaning that they will live only two or three years. However, once planted, hollyhocks usually self-seed, which makes them seem like a perennial. Plant hollyhock seeds directly in the garden any time between late spring and early autumn.
Prepare a spot for the hollyhocks. Choose a sunny spot with well-drained soil. Spade the soil to a depth of 6 to 8 inches. Work 2 to 4 inches of compost or decomposed manure into the soil.
Plant the hollyhock seeds in the prepared spot, allowing 2 feet between each seed. Cover the seeds with no more than 1/4 inch of soil.
Water the seeds immediately after planting. Keep the soil damp until the seeds germinate. After that time, water the plants lightly twice every week. Water in the morning so the foliage has time to dry before evening, as hollyhocks are susceptible to rust if the foliage is allowed to remain damp. Water hollyhocks at the base of the plant and try not to splash the foliage.
Pinch off spent blooms as they appear so that the hollyhocks will continue producing more blooms as long as possible. Prevent rust by keeping the area around the hollyhocks neat, and pick up any plant debris. Cut the hollyhocks down to the ground after the plants are finished blooming in autumn.
Cover the plants with 1 to 2 inches of mulch, such as straw, shredded bark or pine needles, after the first frost in autumn to protect the roots during the winter. Protecting the roots is especially important if the seeds were planted late in the summer. Remove the mulch in the spring to provide air circulation and prevent rust.