Common name: Sweet alyssum
Latin name: Lobularia maritima
Plant size: Under 6″
Plant type: Annual
USDA Hardiness Zones: 9-11; grown as an annual in colder Zones
Cultural needs: Almost any well-drained soil; full sun to part shade
Originally from southern Europe, sweet alyssum has naturalized throughout the US as a hardy annual, reseeding year after year, blooming spring through fall, or year round in warmer Zones. Although mature plants withstand some frost, eventually they become “woody” and require shearing back and then replacing, but seeds self sow everywhere, sometimes invasively. Heat, drought, and deer resistant, compact sweet-alyssum plants fit almost anywhere in the railway garden, especially when using the smaller varieties like L.m. ‘Easter Bonnet’ (white, rose, purple pastels) or L.m. ‘Easter Basket’ (purples), which often remain under 5″ high. Useful as micro-container plants, next to a building, in a rock wall, or massed in a border, as in the photo, sweet alyssum’s best quality is its honey fragrance, a powerful scent for such small flowers. Butterflies like them, too. Buy sweet alyssum at almost any garden center. Look for plants that have not bloomed out, but are just starting to bloom, or shear back the leggy stems.