Whether you call it sweet alyssum or carpet of snow, these low-maintenance flowers add beauty to any garden or landscape. To properly care for alyssum, provide it with well-draining soil, an inch of total water per week, at least six hours of sun daily and some afternoon shade for warm regions. (The last item also makes it spread less aggressively.) You don’t need to mulch alyssum; it works well as “living mulch” for tall plants or as edging.
The only time you typically must worry about pests is when the plant is stressed, which can attract aphids and cyclamen mites. Poorly draining, soggy soil increases the risk of diseases like downy mildew, rot and club root.