Sweet alyssum is a wonderful cool-season annual that has been a long-time favorite because of its dainty blossoms on tidy mounds of foliage. These plants make excellent landscape edging plants in the garden and even in containers. Plant them in masses to create an abundance of its light honey fragrance. Sweet alyssums also will draw all sorts of pollinators to your garden.
Alyssum flowers are most often found in a crisp, clean white. However, sometimes you will see deep purple, light pink, or even soft peachy hued varieties. The abundant white blooms make this plant easy to use in garden designs because they can truly go with everything. Put them at the bases of plants to cover the ground and draw even more pollinators to your garden. Sweet alyssum is also valuable for its early spring blooms when nothing else has taken off.
Sweet Alyssum Care Must-Knows
Alyssums are easy plants to start from seed. Because they are cool-season annuals, they can be sown directly in your garden a few weeks before the last frost date for your area. They don't mind the cold, as long as it isn't a hard freeze. If you want an even quicker impact in your garden, start seeds indoors 5-6 weeks before the last frost date. It is best to plant alyssum in well-drained soil, keeping plants evenly moist throughout the season.
Related: Winter Flowers for the South
Be sure to give your alyssums plenty of sunshine. In northern climates with mild summers, full sun is ideal, which allows plants to keep blooming as much as they can. In areas where summers are on the warm side, plant alyssums in part shade, especially protected from the hot afternoon sun. This helps extend your bloom time a little longer. If the season does get too hot and plants stop blooming, shear plants back by about half. This will encourage new growth and give your plants a good base to bloom again once cool weather returns in fall.
Because alyssum is a cool-season annual, plants will generally stop blooming to conserve energy in the summer. However, there are some varieties that are much more tolerant of the heat and will give you more bloom time. In most cases, varieties with darker-colored blossoms tend to have less heat resistance than the pure white varieties.
Because sweet alyssum is such a popular bedding and container plant, there has been a lot of research done in trying to make them even better for the garden, most of which has focused on creating varieties that are more heat tolerant and continue to bloom throughout the summer. Varieties like 'Snow Princess' have been breakthroughs in this area, and have proven to persist through the summer. Soon, there may even be varieties in other colors than white that will bloom into the fall!