Lobularia–commonly called sweet alyssum–has fragrant white blooms from late spring to early fall. Sweet alyssum is a ground-hugging perennial, grown as an annual. It has narrow mid-green leaves and is considered invasive in some areas.
Lobularia maritima is a perennial but is generally grown as an annual. The plants grow 4 to 10 inches tall. If flowers freely from early spring until late summer. It blooms before many other spring flowers, The flowers are sweet-scented.
Lobularia is very easy to grow. it can be used for edging and is excellent for window boxes, baskets, and carpet beds.
Lobularia grows readily from seed but can also be propagated by cuttings or layering. Sow seed outdoors after all danger of frost is past. It grows best in well-worked, fine-grained soil.
Get to Know Lobularia
- Plant type: Annual
- Growing Zones and range: 2-11; grow as an annual in Zones 2-9, grow as a perennial in Zones 10-11.
- Hardiness: Tolerates light frost without damage to leaves or flowers; killed by hard frost and temperatures in upper 90sF.
- Height and width: 3 to 12 inches (7.6-30cm) tall; 8 to 18 inches (20-45cm) wide
- Foliage: Narrow, linear-lance-shaped to oblong, light to mid green leaves
- Flowers: Clouds of small, cross-shaped, 4-petaled, flat blossoms on rounded heads often scented
- Flower colors: White, cream, rose, pink, purple, violet, and lavender
- Bloom time: During cool weather; some cultivars tolerate heat and bloom all summer; year-round blooms in Zones 9-11.
- Uses: Edging, borders, best in crowded masses, tucked into walls or crevices, rock gardens, containers
- Common name: Sweet Alyssum
- Botanical name: Lobularia maritima
- Origin: the Canary Islands and the Mediterranean
Where to Plant Lobularia
- Grow Lobularia in full sun. Grow Lobularia in full sun in Zones 2-5; plants tolerate light shade in Zones 6-11.
- Plant Lobularia in average, well-drained garden soil.
- Use Lobularia as edging at the front of a bed or border.
- Lobularia is useful for the edges of paths and drive and to fill paving cracks.
- Lobularia is very tolerant of maritime conditions.
When to Plant Sweet Alyssum
- Set established Lobularia in the garden in spring after all danger of frost has passed.
- Start seeds indoors 6 to 8 weeks before the last frost.
- Sow seed outdoors where they will grow about a month before the last expected frost or a few weeks later.
- Set plants started indoors outdoors when daffodils bloom or later; harden off young plants before transplanting them into the garden.
- In mild winter regions, sow and set out alyssum any time of the year except when temperatures regularly exceed 94°F (34°C).
Planting and Spacing Sweet Alyssum
- Sow seed no more than 1/8 inch deep; keep the temperature at 65° to 75°F (18-24°C) until seeds germinate.
- Start seed indoors a few inches under a fluorescent light. Grow plants one to a pot indoors for best development.
- Outdoors plant seeds an inch (2.5cm) or more apart and cover with 1/8 inch of soil, pressed down. Do not let the seedbed dry out.
- Thin and transplant seedlings when they are 2 inches (5cm) high.
- Space Lobularia 8 to 18 inches apart.
How to Water and Feed Lobularia
- Lobularia needs moderate moisture; keep the soil evenly moist.
- Fertilize Lobularia lightly every 4 to 6 weeks or work a slow-release fertilizer into the soil in early spring.
- Mulch plants with chopped leaves or aged compost to keep the soil moist.
- Shear off the tops of plants if they become too straggly; this will stimulate new growth and flowers.
- Lobularia is rarely bothered by pests or diseases.
- Mulch around Lobularia to conserve soil moisture.
- Lobularia will grow tall and leggy when temperatures average 80°s; cut the plants back by half to rejuvenate and promote further blooms.
- Lobularia reseeds in optimal conditions.
- Downy mildew and caterpillars sometimes attack Lobularia.
- Grow Lobularia from seed. Seeds germinate in 8 to 10 days.
- Propagate from root cuttings 4 to 6 inches (10-15cm) long in a dampened mixture of sand and compost at temperatures between 50° and 70°F (10°-21°C).
Lobularia Varieties to Grow
- Lobularia maritima cultivars include white, purple, and rose blossoms, some listed below:
- ‘Carpet of Snow’ spreads tiny white flowers in clusters.
- ‘Easter Bonnet Series’ company plants with white, reddish, purple, or pink flowers.
- ‘Sweet White’ is an old-fashioned, sweet-smelling variety.
- ‘Royal Carpet’ has rosy-colored blooms, blooms early, and is long-lasting.
- ‘Wonderland’ has wide mats of rosy red, purple, or white blooms.