Sweet Alyssum

Sweet Alyssum, scientifically known as Lobularia maritima and belonging to the mustard family Brassicaceae, is a highly popular, low-growing herbaceous annual or short-lived perennial. Native to the Mediterranean region, Macaronesia, and the Canary Islands, Sweet Alyssum is cherished by gardeners worldwide for its incredibly dense, carpet-like mounds of tiny, honey-scented blossoms that bloom continuously from early spring until the first winter frost.

Growing as a spreading ground cover, Sweet Alyssum typically reaches heights of only 3 to 9 inches while spreading up to 12 inches wide. The plants feature highly branched, fine stems covered with small, narrow, lanceolate grayish-green leaves. The tiny, four-petaled flowers are arranged in compact, rounded terminal clusters (racemes). While white is the most classic and fragrant color, cultivars also feature shades of pink, lavender, violet, and deep purple. The foliage is soft and entirely free of thorns or prickles.

The reproductive morphology of Lobularia maritima is represented by the floral formula ⊕ ⚥ K4 C4 A2+4 G(2). The flowers are radially symmetrical (actinomorphic) and bisexual. The calyx features 4 free sepals, and the corolla has 4 free petals arranged in a cruciform (cross-like) pattern. The androecium contains 6 stamens in a tetradynamous arrangement (4 long inner stamens and 2 short outer stamens). The gynoecium consists of 2 fused carpels with a superior ovary, which matures into small, flat, circular to oval seed pods known as silicles.

Sweet Alyssum is a highly resilient and adaptable cool-season plant. It thrives in full direct sun to partial afternoon shade, especially in hot-summer regions where afternoon heat can cause the blooms to fade. It grows successfully in average, sandy or loamy, well-draining soils with a neutral pH, and is highly tolerant of drought and coastal conditions once established. It is easily grown from seeds sown directly outdoors. It is grown as an annual in most US zones but survives as a perennial in USDA zones 9 through 11.

For families with pets, Sweet Alyssum is a 'gold standard' non-toxic plant. It is classified as completely safe and non-toxic to cats, dogs, and horses by the ASPCA Animal Poison Control Center. Curators of pet-friendly gardens can plant Sweet Alyssum along borders, paths, and play areas without any risk of chemical poisoning if chewed on by curious animals. In addition, its intense honey-like fragrance is a powerful attractor for hoverflies, wild bees, and other beneficial predatory insects.

Sweet Alyssum is easily identified by its ground-hugging carpet of tiny, honey-scented four-petaled flowers and fine gray-green foliage. In cottage gardens, it pairs beautifully as a living mulch at the foot of tall vertical bloomers like Larkspur, Snapdragons, and Hollyhocks. To study more low-growing annuals and border companions, browse our comprehensive Flower Identifier.