In short
- A low, creeping annual ground cover 8–15 cm tall.
- Flowers profusely and smells of honey from May until the first frosts.
- An excellent melliferous plant — attracts bees, butterflies and beneficial hoverflies.
- Likes sun and free-draining soil, tolerates short drought.
- Very easy to grow from direct sowing, self-seeds readily.
Botanical data
- Family
- Brassicaceae (Brassicaceae)
- Height
- 0.08–0.15 m
- Width
- 0.2–0.3 m
- Habit
- Creeping
- Growth rate
- Fast
- Position
- Full sun, Partial shade
- Soil
- Sandy, Humus-rich, Loamy
- pH reaction
- pH 6–7.5
- Moisture
- Dry, Moderate
- Bloom
- May–October
- Hardiness
- USDA 9a–11b
- Propagation
- From seed
Characteristics
The plant forms low, spreading clumps with thin, heavily branched shoots and small, narrow-lance-shaped, grey-green leaves. The numerous small, four-petalled flowers are gathered in dense, globular clusters at the shoot tips and give off a distinct, sweet, honey scent. They are most often white, but cultivars can be purple, lilac and pink.
Growing and care
Watering
It tolerates short drought, but in prolonged heat and dryness it stops flowering and sets seed. Water moderately when the top layer of soil has dried out; avoid constant moisture.
Fertilizing
Moderately — excess nitrogen gives lush leaves at the expense of flowers.
Planting
The very fine seeds are sown shallowly and only lightly covered — they germinate in the light. The plant is undemanding and tolerates average, free-draining garden soil.
Pruning
Cut the whole clumps back by about a third and water them — the plant quickly regrows and sets a second flush of flowers.
Companion plants
Good companions
In the same sunny, free-draining spot, aubrieta flowers in spring and alyssum takes over in summer and autumn — together they give continuous flowering along an edge or rock garden.
Alyssum is a well-known plant that attracts beneficial insects — its nectar draws hoverflies and small wasps whose larvae eat aphids, which helps protect vegetables. The effect is confirmed by studies of companion planting.
A classic combination for boxes and pots — the low, white alyssum softly overgrows the edge of the container at the feet of taller pelargoniums.
Bad companions
Constant moisture encourages rot and fungal diseases in this Mediterranean plant accustomed to free-draining, drying-out ground.
The evidence level indicates whether the relationship is backed by research, observation, or gardening tradition.
Diseases and pests
Toxicity
| For whom | Level | Notes |
|---|---|---|
| Humans | None | — |
| Dogs | None | — |
| Cats | None | — |
History and origin
The species comes from the coasts of the Mediterranean and the Canary Islands, where it grows on sand and coastal rocks. It was formerly placed in the genus Alyssum (as Alyssum maritimum), hence the still-popular trade name alyssum. As an easy and rewarding bedding plant it spread to gardens all over the world.
Uses
Ideal for bed edges, for gaps between paving slabs, for walls, for balcony boxes and pots, where it softly overgrows the edges. Planted in masses it gives a fragrant, white carpet; it also works well as a plant that attracts beneficial insects in the vegetable garden.
Trivia
- Although grown as an annual, in a mild climate it is sometimes a short-lived perennial and can overwinter.
- Sweet alyssum is sown in rows of vegetables as a plant that attracts the natural enemies of aphids — one of the better-documented examples of using flowers in biological crop protection.
Frequently asked questions
How do you encourage alyssum to flower again?
When flowering weakens in midsummer, simply cut the whole clumps back by about a third and water them. The plant quickly regrows and sets a second, abundant flush of flowers, which lasts until the frosts.
Does alyssum need to be grown from seedlings?
This is not necessary. Alyssum germinates very easily from direct sowing into the ground in April and May. The fine seeds are sown shallowly, because they need light to germinate, and only lightly covered.
Is sweet alyssum toxic?
No. The plant is non-toxic and considered safe for people and pets, and its flowers are a valued source of nectar for pollinating insects.
Sources
- Plants of the World Online (POWO)Database (GBIF, POWO…)
- RHS — Lobularia maritimaInstitution / botanical garden
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