Alyssum is a hardy flowering annual plant which is frequently used in landscaping, especially in Mediterranean regions. Some varieties of the Alyssum genus have distinctive scents which gardeners find quite pleasing, and the fast growing flowers are often planted in large blocks to provide scent and color. Alyssum thrives in USDA Zones three to nine, and in warmer regions, it can be grown as a constantly flowering perennial, as long as the plants are well maintained. The plant has a sprawling growth habit which is low to the ground, making it ideal for edging flower beds.
With the except of one plant, all flowers commonly called alyssum are in the genus Alyssum. The exception to the rule is sweet alyssum, which is sometimes labeled as Alyssum maritima, but more commonly split out as Lobularia maritima. Sweet Alyssum is a distinctively sweetly scented alyssum with white to purple flowers, and is one of the most common varietals cultivated. Other varieties of alyssum have flowers ranging in color from white to yellow to deep purple, although all species have characteristic tight clusters of flowers, and a creeping habit which will allow the plant to quickly take over an area of the garden if left unchecked.
Along with other plants in the mustard family, alyssum is deer and drought resistant, and will grow in almost any environment, although it suffers in frost. If the dead flowers are regularly trimmed back, the plant will keep blooming for many months, shedding large amounts of seeds as well. These seeds can be harvested and used to start seedlings to replace the alyssum after it dies back entirely in regions with cold winters. In warmer regions, vigilant pruning will allow alyssum to flourish year round.
Full sun to partial shade is the preferred growing environment for alyssum, which grows in any type of soil. Because it functions as a ground cover, alyssum can be used to prevent weeds from taking over flower beds, and will also help to keep healthy topsoil in a garden. It can also be grown in hanging flower boxes, and will develop long hanging tendrils of flowers which can be aesthetically pleasing.
Most varieties of alyssum use “alyssum” in their name, with a qualifier such as Creeping Basket of Gold, Rosie O’Day, or Hoary added to distinguish the species from other alyssums. Another common name for alyssum is madwort, because in medieval times, the plant was associated with cures for rabies and insanity. In some parts of the world, alyssum is still called madwort, while in others, the term “madwort” refers to Asperugo procumbens, an unrelated herb in the borage family.