Grow Sweet Alyssum in the Fragrant Flower Garden

Purple Sweet Alyssum
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The Brassicaceae family is not known for its fragrant members, at least if you're referring to pleasing fragrances. Cabbage, Brussels sprouts, and horseradish are just a few notable aromatics in this broad plant family. However, at the other end of the spectrum, flower gardeners crane their necks for a whiff of the pleasing scents of ornamental plants in this family, including scented stock, candytuft, and sweet alyssum (Lobularia maritime). 

Also known as carpet flower and sweet Alison, the dainty flowers of sweet alyssum emit a honey-like fragrance that’s potent, but not cloying. The rich nectar in the flowers draws legions of beneficial insects to the garden, making it a favorite of organic gardeners. Sweet alyssum is native to Southern Europe, but now grows as a wildflower in many parts of the United States. The flowers rarely exceed the diameter of a pencil eraser, and can grow in clusters that can number in the hundreds on a single plant. Flowers have only four petals, but they can completely obscure the narrow leafed foliage.

How to Plant Sweet Alyssum

Although you can buy nursery packs of young sweet alyssum plants, they are easy to start directly in the garden from seed. Choose a location with full sun or afternoon shade. Lightly press the fine seed into the soil when all danger of frost is past, and keep moist until germination occurs, usually about a week after sowing. Blooming usually occurs about six weeks after sowing, as plants reach their mature height of four to eight inches. You can expect flowers throughout the growing season, but blooms are heaviest in mild spring and autumn weather.

Sweet Alyssum Varieties to Try

'Dark Knight' is an exciting new purple cultivar introduced by Proven Winners that blooms all summer, even in hot areas, without the need for deadheading. ‘Snow Crystals’ features vigorous plants with white flowers larger than heirloom types. 'Trailing Rosy Red' is ideal for hanging baskets, as its name suggests. Gardeners who crave yellow flowers should seek out the 'Aphrodite' series, which features this and other pastel tones. If you're looking for a reliable edger for tidy paths try the 'Easter Bonnet' series, which maintains a pleasing mounded shape. 

Garden Design With Sweet Alyssum

The propensity of sweet alyssum to form a mat without becoming invasive makes it an excellent filler plant in the garden. Tuck it between newly planted perennials to temporarily fill blank spots in the landscape, or plant it beneath roses to disguise unsightly canes. If you have a stacked rock wall, fill pockets with soil and firmly insert the root ball of two or three sweet alyssum plants. 

Sweet alyssum also thrives in containers, growing and blooming quickly alongside cool weather annuals like pansies, snapdragons, and violas. The cool pink, purple, and white tones of sweet alyssum plants are a stunning companion for silver-foliaged plants like dusty miller and wormwood.

Fairy gardens have never been more en vogue than they are now, and the sweet alyssum plant is the perfect scale to serve as tiny shrubbery for your small garden world. Its slightly trailing habit means you can train the plants up a small trellis for a faux vine effect in a fairy garden or terrarium. Conversely, a small sweet alyssum plant tumbling over a teacup's edge adds cheer to a kitchen windowsill.

The blooms of sweet alyssum make an excellent flowering companion for the edible garden for two reasons: The pollinators your sweet alyssum attracts will stop by fruit trees, herbs, and vegetable plants, providing necessary cross-pollination and increasing productivity. Also, the shallow blooms of sweet alyssum are just the right size for nourishing tiny parasitic wasps, which will then deposit their eggs on the caterpillar pests upon which they feed.

Sweet Alyssum Care Tips

Keep newly planted sweet alyssum evenly moist until plants are established. Although sweet alyssum plants can withstand some dryness, they may look a bit ragged and may even start to shed flowers if you don't provide adequate moisture. Watch your foliage for plant health cues: yellow foliage means the plants are too dry, while purple foliage indicates the growing temperatures are too cold.

Plants affected by drought stress may also attract whitefly pests. If this happens, avoid using pesticides that would affect pollinators, and instead spray them away with a jet of water or use a hand vacuum to remove them. 

Many sweet alyssum plants will look shaggy by midsummer. Don't cling to the vision of a few stray blooms on the plant; you must sacrifice these and shear them back to promote heavy fall blooming.