Annual plants also known as Sweet Alyssum.
Season & Zone
Exposure: Full sun or partial shade.
Zone: 3-10, not winter hardy
Start indoors 6-8 weeks before the last frost, around the beginning of March to early April here on the coast. Transplant out after all danger of frost has passed. Or, direct sow while some danger of light frost still exists. It's very easy, either way.
Sow seeds on the surface of the soil. If starting indoors, use a sterilized seed starting mix and maintain a soil temperature of 12-21°F (55-70°F) under bright lights. Seeds require light to germinate, so do not cover them. They should sprout in 5-14 days.
Transplant 20-30cm (8-12") apart once all risk of frost has passed. Watch for slug damage in the early spring. Alyssum prefers a moist loamy soil with a pH in the 6.0-7.0 range, but it's adaptable. It is tolerant of dry soil, and can be used for xeriscaping. If growth slows in mid-summer due to heat, shear plants back by half to encourage compact growth and a second bloom. May self sow.