Lobularia maritima 'Snow Crystals'
Common Name: sweet alyssum 
Type: Herbaceous perennial
Family: Brassicaceae
Zone: 5 to 9
Height: 0.25 to 0.75 feet
Spread: 0.50 to 1.00 feet
Bloom Time: April to June
Bloom Description: White
Sun: Full sun to part shade
Water: Dry to medium
Maintenance: Medium
Suggested Use: Annual
Flower: Showy, Fragrant
Tolerate: Drought, Dry Soil


Annual. Easily grown from seed in average, medium moisture, well-drained soils in full sun to part shade. Best with some part afternoon shade in the St. Louis area. Tolerates dryish soils. Sow seed directly in the ground several weeks before the last frost date. For earlier bloom, start seed indoors 5-6 weeks before last frost date. Nurseries sell starter plants in cell/six packs. Set seedlings or purchased plants out just before last frost date. Shear plantings after first bloom to encourage a second flush of bloom. Blooms spring to frost in cool summer climates. Flowering and plants usually decline significantly in the dog days of a typical St. Louis summer at which point they should be cut back by one half. Plants usually revive as cooler fall temperatures arrive. Seed may also be sown in August for fall bloom.

Noteworthy Characteristics

Lobularia maritima, commonly called sweet alyssum, is one of the easiest annuals to grow. It is a mat-forming plant that produces spreading mounds of well-branched stems clad with linear, lance-shaped, gray-green leaves (to 1” long). Plants typically grow 3-9” tall to 12” wide. Dense clusters of sweetly fragrant, tiny, white 4-petaled flowers cover the foliage mounds from spring to early summer. Flowering is often so profuse as to totally hide the foliage. Cultivars expand the flower color choice to include shades of pink, rose, lavender, purple and apricot. Synonymous with Alyssum maritimum.

Genus name comes from the Latin word lobulus meaning small pod.

Specific epithet means of the sea or coastal.

‘Snow Crystals’ was the first tetraploid sweet alyssum and has lots of vigor. It is known for its greater heat and wind tolerance, larger flower size, and longer staying power. White blooms cover 8-10 inch mounds and plants flower all season from June to frost. It has been awarded the Fleuroselect Gold Medal.


No serious insect or disease problems. Damping off is an occasional problem with seedlings.


Mass in border fronts or rock gardens. Underplanting. Edging and bedding. Mixed containers.