Red sweet William in a spring garden.

Overview

Sweet William is a part of the genus Dianthus, which includes many species of annual, biennial and perennial flowers. They range in height from 6 to 18 inches tall, producing flat, round petals that are 1 inch across with fringed edges in pink, white, red or multiple colors. Sweet William are easy to grow, but require protection from poor soil, over-fertilizing and pests.

Step 1

Amend the soil about one month before planting sweet William. They thrive in rich, well-draining soil. Dig up the soil and incorporate generous amounts of well-rotted compost or manure. If the soil is heavy clay, add peat moss as well.

Step 2

Apply a complete plant food in the early spring, when the begin active growth begins. Be careful not to over-fertilize, as these flowers are sensitive to excess nitrogen, which can cause brown leaf tips to develop.

Step 3

Protect sweet William from aphids and slugs. Spray the flowers with malathion to treat for aphids. Spread a circle of crushed eggshells or diatomaceous earth to prevent slugs from attacking the flowers.