Sweet William (Dianthus barbatus) consists of over 300 species of flowers including the carnation (the common name refers to Prince William, Duke of Cumberland (d. 1765), who put down the Jacobite risings). Originating in southern Europe and Asia, with some varieties found as far north as Russia, Sweet William is a biennial that comes in a variety of pink colors.
Sweet William is a biennial plant with a two-year life cycle, producing only leaves in the first year. Sweet William plants, which look very similar to carnations, can be grown from seeds, cuttings or plant divisions. If planting seeds, plan on starting them indoors six to eight weeks before the last frost for spring blooms. The young seedlings generally transplant well and can be set outdoors after the last frost. Seeds sown in the first year bloom in the spring of the second year.
Sowing should take place between April and June. Sprinkle the seeds on to well-watered seed compost in a seed tray. Cover very lightly and place the tray in an ambient position out of full sun: these seeds germinate best in temperatures of 64°F-68°F (17°C-19°C) and not in fierce heat. Once the seedlings are large enough, with two true leaves, prick out into individual small pots. When the roots reach the bottom, plant them into the garden. One of the best ways to enjoy Sweet William is to mix the seeds together, creating a colourful array of pink, white, purple and mauve.
Flowering period is between June and July. One major drawback for most gardeners is the Sweet William is biennial, meaning you need to plant it one year and wait until the following season for flowering. Sweet William is frequently used in landscaping and flower displays, as its height makes it perfect for flower arranging. Sweet William is perfect for borders, cottage style gardens, and rock gardens.
The bad news is that they are relatively short-lived (even as perennials). The good news is that the plants often reseed themselves, eliminating the need to buy new ones for planting. Just leave the dried blooms in place.
Secrets of success
Noteworthy characteristics: Various cultivars produce colorful and disc-like blossoms, which are decoratively fringed and intensely fragrant. They are equally stunning as single colors, bicolors, or in a mixed palette.
Soil type: Clay, loam, sand, silt.
Light: Sweet Williams prefer full sun, but will tolerate light shade.
Care: Grow in fertile, moist but well drained soil in full sun. Needs low watering.
Propagation: Sow seed of biennials in summer; plants will bloom the following year.
Attracts: Butterflies, hummingbirds, visual attention.
Problems: Crown rot, slugs, sow bugs, grasshoppers, chipmunks, squirrels, deer.