Sweet Alyssum

(Brassicaceae [also known as Cruciferae] - Mustard Family)

Large View

• Form
  • small herbaceous annual
  • maturing at about 4" tall by 1' wide
  • prostrate mat or mounding mat growth habit
  • medium growth rate

• Culture
  • full sun to partial shade
  • prefers a moist, well-drained soil in partial sun, with occasional irrigation during the hottest and driest portions of the Summer
  • propagated primarily by seeds, and has a low level of self-sowing from one year to the next
  • Mustard Family, with virtually no disease or pest problems in the landscape
  • abundantly available in flats and seed packets
  • flowering will decline in intensity and growth will stop in mid-Summer during periods of heat and drought; during these times, a light shearing of the terminal growth, along with irrigation and light fertilization, will assist the shallow root system in maintaining plant vigor until slightly cooler weather allows for resumption of heavy flowering (most members of the Mustard family are cool-season plants)

• Foliage
  • medium green, alternate, small to miniature, lanceolate to narrow eliptical on thin stems, with no petioles, and mostly obscured once heavy blooming has started

• Flowers
  • the white, lavender, rose, or violet miniature flowers are four-petaled (with the petals of equal size), in dense clusters at the stem termini and slightly fragrant (hence the common name)
  • flowering is heavy and creates an overall carpeted effect when in bloom from May until mid-Autumn freezes (intense Summer heat and repeated frosts will reduce the intensity of flowering during these times, but not stop it)

• Fruits
  • ornamentally insignificant, but some amount of self-sowing may occur from one year to the next

• Twigs
  • not applicable

• Trunk
  • not applicable

• ID Summary
  • prostrate annual with small linear leaves and miniature four-petaled flowers, usually white, lavendar, or rose in color, creating a carpeted floral effect and often used as an edger for the annual bed

• Function
  • edging, filler, mass planting, embankment cover, rock garden rambler, and cascader over a wall, planter, or hanging basket

• Texture
  • fine texture
  • thick density

• Assets
  • profuse flowering starts in mid-Spring before the plant is fully established, and continues throughout most of the Summer until initial frosts, when reduced flowering continues
  • flowers are mildly fragrant, especially when the evening dew diffuses their perfume

• Liabilities
  • in the heat of the Summer, flowering may nearly stop and plants go into a decline or semi-dormancy until cooler weather returns (irrigation, light fertilization, and light shearing will alleviate this condition)
  • the center of the clump tends to split apart and have no flowers as the season progresses, which is noticeable when it is used as an edger
  • self-sowing nature from one season to the next (this can also be the asset of a "repeat annual" if desired, although floral color may be slightly different due to hybridization, and the number of plants germinated will be much reduced as compared to the previous year's planting from plugs)

• Habitat
  • native to the Mediterranean
  • annual that is killed after several hard freezes, but not with frosts

• Alternates
  • profusely flowering, ground-hugging herbaceous plants that serve as edgers or short cascaders (annuals include Lobelia erinus & Nierembergia hippomanica, while perennials include Aurinia saxatilis 'Compactum', Campanula carpatica 'White Clips', Iberis sempervirens 'Purity', Platycodon grandiflorus 'Sentimental Blue', etc.)

• Variants
  • several exist, primarily selected for floral color, compactness, early bloom, and floral vigor
  • Lobularia maritima 'New Carpet of Snow' - white-flowering, compact form

• Translation
  • Lobularia translates as "a small pod", referring to the miniature fruits.
  • maritima translates as "growing by the seashore".
  • formerly known as Alyssum maritimum, where Alyssum translates as "not madness", referring to its purported ability to cure rabies.

• Purpose
  • Sweet Alyssum is a classic edging annual that can also be used in mass plantings, or as a short cascader in wall, planter, or hanging basket situations.

• Summary
  • Lobularia maritima is known as a prolifically flowering prostrate annual, often serving as an effective edging plant that "faces" larger annuals, having a prolonged flowering period in sunny sites.