About Alyssum
Lobularia maritima, a resilient annual, belongs to the cabbage family. Once mature, alyssum displays an abundance of delicate blooms that gracefully spill over pots, serve as garden edging, or blanket groundcover. Its dense growth effectively suppresses weeds.
Alyssum plants act as a natural pest control solution in the vegetable garden, effectively managing aphid infestations. Their pollen and nectar attract parasitic wasps and syrphid flies, which feed on aphids while enjoying the nectar as a food source.
When to Plant Alyssum Seeds
Plant outdoors once all risk of frost has passed, or start indoors five to six weeks before the last frost.
Where to Plant Alyssum Seeds
Plant Alyssum seeds in full sun whenever possible (6 to 8 hours per day), although it tolerates partial shade (4 to 6 hours per day). Opt for well-draining, acidic soils, as Alyssum thrives in rocky and sandy conditions. It grows particularly well on slopes and in rocky garden environments that may not suit other landscape plants.
How to Plant Alyssum Seeds
Due to their small size, Alyssum seeds are challenging to count. Scatter approximately four to eight seeds onto the surface of a general seed starting mix and gently press them no deeper than 1/8th of an inch. Avoid burying the seeds, as exposure to sunlight is necessary for germination. Water them gently using a plant mister to avoid displacing them or washing them away. Learn more about germination light requirements here.
If starting indoors, plant your Alyssum seeds in a tray with a humidity dome cover and place it in a bright, warm south-facing window. Alternatively, use grow lights or a seedling heat mat if it's cold or cloudy. Maintain temperatures between 55°F and 70°F. Once seedlings emerge, remove the cover and gently thin them out to one every six inches. Harden off the seedlings before transplanting them into the garden after the danger of frost has passed. Read more about how to harden off seedlings here.
When transplanting young seedlings or starting seeds outdoors, do so after all danger of frost has passed. Space Alyssum plants six to eight inches apart for optimal growth. Alyssum is adaptable and can tolerate most soils, provided they are well-draining.
How to Care for Alyssum
Alyssum is a low-maintenance plant suitable for xeriscaping. Water sparingly but deeply, as its roots prefer drying out between waterings, especially in partial shade. Avoid consistently damp or soggy soil to prevent root rot. During hot summers, adjust watering as needed, but avoid over-pampering. Light pruning and deadheading can promote additional blooms. Despite being annuals, Alyssum reseeds heavily and returns each year.