Sweet alyssum

Sweet alyssum is the plant that spills over the rim of a pot in a foam of tiny flowers, and it smells like honey when the sun hits it. Clemson plants it along the edge of a pot or window box and lets it cascade. White is the classic and the most fragrant, and there are lavender, pink, and purple kinds. It also pulls in bees and the small wasps and flies that eat aphids, which vegetable gardeners like.

In the Upstate

Alyssum is a cool-season plant here. Clemson sows it in September for fall and winter flowers, and NC State rates it for zones 5 to 9, so a normal Greenville winter is fine and it keeps blooming through the mild spells. A hard freeze can knock it back, and a pot is a zone colder than the ground, so do not count on it coming through January untouched. The old seed-grown types stop flowering when summer heat arrives. The newer sterile hybrids Clemson names, Snow Princess and the Stream series, are bred to take heat and last through summer, so pick by the season you want.

In a container

Alyssum is a trailer. Plant it at the edge so it can hang, or tuck it between taller plants as a filler. Seed types stay 3 to 6 inches tall and spread about a foot, while the hybrids reach 12 inches and sprawl 2 to 3 feet, so one plant per corner is enough. Water regularly, but the mix must drain, since NC State says very good drainage is a must. If it gets thin in a warm spell, cut it back and it usually refills.

Care

Water regularly but let the surface dry between, feed monthly with an all-purpose fertilizer through the growing season, and shear off spent flowers to keep the mound tidy and blooming. The thing that kills alyssum is a wet crown: stem and crown rot from a pot that never dries, or from drowning it in a rainy week. Drought or a hot spell only stops the flowers, and a trim brings them back.