Hollyhock plants attract many gardeners and landscapers because they are easy to grow and yield tall, showy plants. With the scientific name Alcea rosea, hollyhocks come in a wide variety of colours from dark purple-black to white and every shade of pink, lavender and yellow in between. This variety allows gardeners to mix and match different colours to create a floral rainbow. Though hollyhocks are usually an outdoor flower planted near fences or walls, many gardeners enjoy growing them in pots as well. This means that the hollyhocks can enjoy warm summers outdoors and bloom all winter indoors. Container hollyhocks require slightly different care.
Place a large terra cotta pot with a drain hole into a matching flood tray. The pot must be large because hollyhocks grow tall quickly and have a dense root system. Two or 3 feet deep and wide should be large enough.
Fill the pot about halfway with soil, moisten the soil very slightly, then add a little soil at a time, stirring it with the trowel. This ensures the soil is evenly moist. Fill the pot to about 2 inches below the lip. Do not pack down the soil.
Dig a hole about 5 inches wide and 4 inches deep in the centre of the soil. Remove the seedling from its tray and untangle the root ball slightly with your fingers. Place it in the hole and cover the roots but none of the stem.
Mulch the seedling with about 1/2 inch of mature compost and water until the soil is moist but not soaking. Empty the drip tray immediately. Wait until the top of the soil is dry to the touch before watering again.
Drive a garden stake into the soil about an inch from the seedling. When the hollyhock reaches about 6 inches tall, tie it gently to the stake for support. Replace the stake with a taller one as the hollyhock grows. Set it in a window in full sun.