Sweet alyssum, a low-growing annual flower, has delicate, fragrant blooms in shades of white, pink, lavender, and purple. Often spilling over borders or in containers, it adds beauty. Beyond its ornamental value, sweet alyssum is used in companion planting, a technique where plants are grown together for a more resilient, productive ecosystem.
Why Companion Plant with Sweet Alyssum
Sweet alyssum offers several advantages in garden design. Its small, nectar-rich flowers attract beneficial insects, including pollinators like bees and butterflies, essential for fruiting plants. It also draws in predatory insects such as hoverflies, ladybugs, green lacewings, and parasitic wasps, which feed on common garden pests like aphids, spider mites, thrips, and cabbage worms. This natural pest control reduces chemical interventions, promoting a healthier garden.
Sweet alyssum’s dense, low-growing habit makes it an effective living mulch or groundcover. This growth suppresses weeds by blocking sunlight and retains soil moisture, useful in dry periods. It also regulates soil temperature and prevents erosion, contributing to soil health. Its sweet, honey-like scent adds a pleasant fragrance.
Best Sweet Alyssum Companion Plants
Sweet alyssum pairs effectively with various plants, enhancing their growth and protection. Among vegetables, brassicas like broccoli, cabbage, kale, and collard greens are excellent companions. Sweet alyssum attracts syrphid flies, ladybugs, and parasitic wasps whose larvae prey on common brassica pests, benefiting these crops. Tomatoes and peppers also benefit, as parasitic wasps help control pests like tomato hornworms. Root vegetables like carrots, radishes, and potatoes thrive alongside sweet alyssum, attracting hoverflies that consume aphids, and its fragrance may deter carrot flies.
Herbs like basil, oregano, rosemary, sage, and thyme integrate well. Many herbs share similar growing conditions; their strong scents can repel pests, while sweet alyssum’s flowers attract pollinators, improving herb yields. Sweet peas are another good companion, offering a contrasting vertical element and their own fragrance.
For ornamental pairings, marigolds are a classic choice, deterring nematodes and soil-borne pests. Their vibrant colors contrast with sweet alyssum’s delicate blooms. Lavender, with tall spikes and purple flowers, also provides visual contrast and attracts pollinators. Other flowers like petunias, snapdragons, and pansies are suitable companions, sharing similar light and water requirements, contributing to a diverse floral display.
Tips for Successful Sweet Alyssum Companion Planting
For successful sweet alyssum companion planting, consider all plants’ environmental needs. Sweet alyssum thrives in full sun but tolerates partial shade in warmer climates. It prefers well-drained soil and consistent moisture; mature plants show some drought tolerance. Avoid overly wet conditions, which negatively impact growth.
Appropriate spacing ensures adequate light and air circulation, preventing overcrowding. Sweet alyssum spreads 10 to 48 inches wide; provide 6 to 12 inches between plants for optimal growth. When planting from seed, sow directly outdoors in early spring after the last frost, or start indoors 6-8 weeks before transplanting.
Seeds require light for germination, so press them gently onto the soil surface, not burying deeply. Minimal fertilization is sufficient; rich soil can promote foliage over flowers. Consistent watering, especially during dry spells, supports continuous blooming.