Abundant spring flowers fill a window box in Charleston, SC. The draping white flowers are sweet alyssum (Lobularia maritima).
Barbara H. Smith, ©2022 HGIC, Clemson Extension
The fragrant blooms of sweet alyssum (Lobularia maritima) give this flower its name. This cool-season annual is known for its profusion of white flowers. There are also lavender, pink, and purple blooming varieties available. It pairs well with other spring flowers like pansies, violas, dianthus, snapdragons, etc.
Sweet alyssum can be grown in pots, hanging baskets, and window boxes. Allow it to cascade over the sides of a container. It can also be grown to line a path or in between stepping stones. Plant it where you can enjoy its sweet fragrance.
Sweet alyssum can also be grown in the vegetable garden to attract pollinators like bees and butterflies. In addition, it attracts beneficial insects like parasitoid wasps and syrphid flies. These beneficial insects are biological pest control and reduce the need for pesticides. To read more about them, see Attracting Beneficial Insects.
This purple variety of sweet alyssum is planted in a large pot with red-veined sorrel (Rumex sanguineus).
Barbara H. Smith, ©2022 HGIC, Clemson Extension
Plant sweet alyssum in a sunny location that receives some afternoon shade. It grows best in well-drained soil. Be sure to water regularly. Fertilize monthly with an all-purpose fertilizer throughout the growing season. Deadhead the flowers to encourage more blooms.
Sweet alyssum can easily be grown from seed and should be directly sown in the garden several weeks before the last frost date in spring. Seeds can also be sown indoors 6 to 8 weeks before planting outdoors. The seeds need light to germinate, so only lightly cover the seeds with soil. The plants will flower within 6 to 8 weeks. Seeds can also be sown in September for fall into winter flowers. Sweet alyssum grown from seed reaches 3 to 6 inches high and spreads 12 inches or more. As summer temperatures rise, alyssum grown from seed may stop producing flowers.
Many sterile hybrids are available that have improved heat resistance and will last through the summer. These plants grow larger than those grown from seed, reaching 12 inches tall by 24 to 36 inches wide. They are not available as seeds. Look for Snow Princess® (Lobularia hybrida ‘Inlbusnopr’ PP21,594) and White or Lavender Stream ™ (L. hybrida) plants in your local garden center.
For more information on annuals, see HGIC 1152, Growing Annuals.
