Overview and Description of Sweet Alysum Plants
Sweet Alyssum is a delicate carpet of tiny flowers with a subtle, sweet scent. The low-growing foliage is covered by flowers for much of the growing season. Sweet Alyssum (Lobularia maritima) is very easy to grow, from plant or seed. It is a cool season flower that can be set out in early spring. In frost-free climates, Sweet Alyssum can also be grown throughout the fall and winter.
Most varieties will fade in the heat, but rally again in the fall.
- Leaves: Narrow, lance-shaped, slightly hairy gray-green leaves.
- Flowers: Tiny cross-shaped, 4 petal flowers in white, pale pink and purple, clustered in rounded racemes.
Alyssum, Sweet Alyssum, Carpet Flower
Sweet Alyssum is an annual plant, although some varieties are hardy in frost-free areas. Gardeners in USDA Hardiness Zones 7–11 may have plants that continue growing all year long, but they will be short-lived. Sometimes they self-seed so much that is seems as if the same plants are surviving, when in reality, new seedlings are filling in.
Sweet Alyssum plants will grow in either full sun or partial shade. They appreciate some shade during the hottest part of the day.
Most varieties grow 4–6 inches (h) x 6–9 inches (w)
Sweet Alyssum plants repeat bloom, although many varieties tend to stop flowering in heat.
Sweet Alyssum Growing Tips
Planting: You can start Sweet Alyssum from seed or plant, although some new cultivars are not available as seed. Seedlings are widely available in nurseries, in the spring and often in the fall.
To start Sweet Alyssum from seed, simply scatter the seed and press it down, so that it makes good contact with the soil, but it is still exposed to light.
Keep the soil moist, until germination. Then water whenever the soil feels dry.
You can direct seed outdoors, once the soil feels warm to the touch. You can also start alyssum seed indoors, about 8 weeks before your last frost date. Do not transplant until after all danger of frost. Alyssum is somewhat frost tolerant, once established, but tender transplants are not hardy enough for frost.
Caring for Your Sweet Alyssum Plants
Sweet Alyssum loves full sun, but it does not like prolonged dry periods. To keep it going into summer, provide at least a inch of water every week, more during hot or dry spells.
Your in ground Sweet Alyssum plants should not need any fertilizer, unless your soil is poor. Container alyssum plants will need more frequent water and monthly feedings with a water soluble fertilizer.
Some varieties will readily re-seed themselves, but the plants tend to revert to the somewhat gangly species. Man of the newer hybrids, like Snow Princess™, are sterile, but they have improved vigor and stand up to the heat better than those that put a lot of energy into setting seed.
Sweet Alyssum Design Tips
Sweet Alyssum is a low grower that makes a wonderful carpet-like ground cover. As the plants spread, they will create a living mulch under taller plants.
You can use Sweet Alyssm along edges, in the garden, or to fill nooks and crannies on walkways and walls. If you plant it near stone or anywhere that dries out quickly, you will need to provide some extra water. The tight, free-flowering plants are also great in hanging baskets and containers.
- 'Easter Bonnet' - An early blooming variety, in lavender or white.
- 'New Carpet of Snow' - Low growing variety, covered in white flowers.
- 'Pastel Carpet' - A blend of pinks, lavenders and creams.
- 'Snow Crystals' - Tidy, mounding variety with clear white flowers and good stamina.
- Snow Princess® - A sterile hybrid, from Proven Winners, that stands up well to heat.
Pests & Problems:
Sweet Alyssum is generally problem free. Aphids can become a pest, especially when the plants are under stress.