Sweet Alyssum (aka Lobularia maritima) pronounced Lob-yew-lay-ree-uh mar-rit-im-uh also known as the “Carpet Flower” is a classic garden flower.
The carpet flower produces a pretty, sweet-smelling carpet of tiny flowers in shades ranging from dazzling white to deep purple.
The flowers are attractive to people and pollinators, and with regular, simple deadheading, can grace your garden from early in the spring to well into the autumn.
In mild climates, you may even have some winter blossoms.
In this article we share advice on growing and caring for Sweet Alyssum. We also describe the many merits of keeping this lovely, easy care plant in almost any garden setting. Read on to learn more.
Sweet Alyssum At A Glance
Sweet Alyssum is an annual plant which reseeds itself readily and can grow year round in a mild climate.
It is one of several types of plant are called “Alyssum”, such as Yellow Alyssum (Aurinia saxatilis) which is a rugged, perennial groundcover.
Family: Oddly, all types of Alyssum are members of the Brassicaceae (cabbage) family.
Name: The botanical name of the plant is Lobularia maritima. It is commonly called Alyssum, which is a name with Greek origins. The prefix “A” indicates a negative (i.e. “not”). The suffix, “lyssa” indicates rage.
The plant was so named because ancient Greek folk medicine practices held that the various types of Alyssum could be used to treat rabies. Don’t try this at home!
Common Names: Carpet flower, Snowdrift, Sweet Alison
Foliage: The grayish-green leaves of this plant are nondescript, small, pointy and a bit fuzzy. When the plant is in full flower, you hardly see the leaves.
Flowers & Fragrance: The sweet-smelling individual blossoms are very small, four-petaled and cross-shaped. They come in a wide range of colors and grow close together in rounded, umbrella-shaped clusters.
Sun Requirements: These plants do well in settings ranging from partial shade to full sun. In very hot climates, partial shade is best.
Water Requirements: Keep seeds and seedlings evenly moist. Taper off watering as the plants become more established.
Fertilizer Requirements: Alyssum grown in a well-prepared bed with rich, loamy soil will not need fertilizer. When growing your plants in containers, provide a light, monthly feeding using a water-soluble fertilizer.
Soil Requirements: Alyssum does well in a rich, loamy soil with a neutral pH balance.
Height & Spread: Most varieties grow to be 4-6 inches high and 6-9 inches wide. There are some compact varieties that are a bit smaller.
Blooming Period: In mild climates with regular trimming, these plants will bloom continuously, year round. In cold climates, they die back in winter and may reseed in spring. Excessive summer heat can hamper blooming.
Hardiness: Can be grown successfully in USDA Zones 3-11.
Is Sweet Alyssum An Annual Or A Perennial?
In its natural habitat, Alyssum is considered a perennial; however, in most parts of the United States (and especially in the north) it is treated as an annual.
These plants come from the Mediterranean, so they naturally do better in warmer climates, but they still do quite well in cooler settings.
This plant can be winter hardy in mild climates, and it will reseed itself readily.
This can make it seem as if one plant survives throughout the mild winter and into the spring.
In actuality, the parent plants die back while the seeds quickly take hold and take their place.
In very cold climates, seeds lie dormant in the ground until the warmth of spring awakens them.
13 Popular Varieties Range In Color From Snowy White To Deep Purple
- Snow Crystals present small, neat mounds of bright, white flowers.
- Snow Princess is a sterile hybrid that performs superbly in hot climates.
- New Carpet of Snow produces a thick, low-growing carpet of pretty white blossoms.
- Tiny Tim and Little Gem are excellent compact choices in white.
- Easter Bonnet provides white or lavender blossoms very early in the spring.
- Pastel Carpet blooms in an attractive blend of cream, lavender and pink.
- Bi-Color Pink Stream presents an extravagant pink and purple display.
- Easter Bonnet Deep Pink provides pretty pink blossoms very early in the spring.
- Wonderland Deep Rose has luscious rose-colored blooms.
- Rosie O’Day has lovely lavender/pink blossoms.
- Royal Carpet is a stunning shade of violet/purple.
- Violet Queen has impressive, solid dark purple blooms.
- Purple Shades is another pretty choice in purple.
Do All Types Of Sweet Alyssum Reseed Themselves?
Alyssum is a wildflower in the Mediterranean and reseeds itself readily there. If your plants become well-established, you can expect traditional varieties to return from seed on their own, year-after-year.
In fact, in very conducive environments, they may become invasive.
You can easily grow traditional Carpet Flower from seed in almost any setting; however, if you want to grow one of the new cultivars or a hybrid, you’ll need to purchase seedlings.
Check your local nurseries to find varieties that do well in your area.
One of the best advantages of hybrids is that they withstand adversity better than traditional varieties and grow more vigorously.
This is because they do not usually put energy into producing seed for reproduction.
Hybrid plants may or may not reseed themselves. If they do, you can never be sure of what you will get.
When hybrids reseed, they tend to revert to resemble one parent or another rather than continuing to display the desired combination of traits.
Is It Better To Sow Seed Outdoors Or Indoors?
When the soil in your garden feels warm, you can go ahead and sow Alyssum seed.
If it stays cold in your area until well into the springtime, you may want to start your seeds indoors a couple of months before the last predicted frost.
If you start seeds indoors (or if you purchase seedlings) be sure all danger of frost passes before transplanting your seedlings.
Once Alyssum becomes established, it can be fairly frost tolerant.
However, young seedlings started indoors or purchased from a nursery will not be able to tolerate frost at all.
If you direct sow the seeds outdoors, you don’t need to worry about this. You can scatter them over the surface of well-prepared soil even when there is still some danger of light frost.
You may wish to cover them lightly with sand or mix the seed in with sand or soil to scatter it.
Don’t cover the tiny seeds completely, though. They need exposure to light in order to germinate.
Once the seed is sown, keep the soil slightly moist until the seeds germinate.
When growth is established, check the soil often and provide water when it begins to dry out.
If you start your seeds indoors, it’s best to use a specially prepared starting mix. Set up your starting trays in an area that maintains a steady temperature between 55° and 70° degrees Fahrenheit.
The trays should be kept in a brightly lit area to stimulate germination, and you should see sprouts within two weeks’ time.
How Do You Transplant Alyssum Seedlings?
When your plants have grown at least two sets of true leaves, and all danger of frost has passed, you can move them into your garden.
Prepare your soil in advance. It should be moist and loamy with a neutral pH (6.0-7.0).
Once your plants are established, they will be able to tolerate drier soil.
In fact, Alyssum is a good choice to add color and softness to a xeriscaped yard.
Nonetheless, when you first set your seedlings out, they will need consistent moisture until they take hold.
How To Care For Sweet Alyssum?
Water deeply and infrequently – Even with its love for sun and tolerance for drought, Alyssum cannot survive without water.
During the heat of the summer, provide a deep weekly watering (1″). If it is extremely hot and dry, adjust to provide more water as needed.
Always water deeply, as you would with grass or wildflowers, as this promotes good root growth to help the plants survive drought conditions.
Trim regularly – During the spring and into the early summer, you can expect your plants to grow rapidly and bloom profusely.
In midsummer, when the air is hot and dry, you may notice that growth has slowed and blooms are dwindling.
When this happens, take out your shears and give your plants a trim. Regular trimming helps keep plants flowering for months.
Trim off about a third of the height of the plant. New buds will set and bloom very rapidly.
Replant as needed – Even with a well-established stand of Alyssum, you may wish to turn the soil and start over again from time-to-time.
When left to its own devices, Carpet Flower can begin growing in a gangly, straggly manner after a couple of seasons.
Pests And Problems Are Rare
Generally speaking, Alyssum plants are trouble-free.
If small beetles or earth fleas are a problem in your area, they may be attracted to your young seedlings if you direct-sow your seeds outdoors.
If your plants are stressed, aphids may move in (as they will with any stressed plant). Overall, good, consistent care should keep pests and problems at bay.
10 Ideas For Growing Sweet Alyssum In The Garden
Your imagination is almost your only limit when it comes to using these versatile, easy-care plants successfully in your garden. Try these 10 ideas!
Bees, butterflies and pollinating flies (aka Tachinid Fly) all love the sweet scent of these pretty little flowers, and they provide important nourishment for a wide variety of pollinators.
Grow Natural Mulch
Planting Carpet Flower around taller plants, shrubs and trees and in your veggie garden provides soil protection and water retention in the form of a natural, living mulch.
These low growing flowers are ideal for delineating your flower beds, lining walkways or surrounding the patio with fragrant flowers.
Fill Containers With Color And Scent
On their own or used as an edging around taller container plants, Alyssum provides a pretty, sweet-smelling addition to window boxes, hanging baskets, planters, flower pots and more.
Frame Taller Plants
Planted in front of taller plants, Alyssum obscures uninteresting stalks and foliage and (when carefully color coordinated) brings out the best in companion plant blossoms.
Give Your Rock Garden A Color Pop
Although Alyssum may not reseed itself well in a rocky setting, used as an annual, the plants can add a dash of color to a rock garden through the spring and summer.
Create A Patriotic Theme
In white, Sweet Alyssum planted with blue ageratum and red salvia is a classic combination for creating living decorative arrangements for the 4th of July or for adorning veteran’s cemetery plots on Memorial Day.
Brighten Your Moon Garden
A moon garden is typically planted with sweetly scented, pale flowers. Alyssum is the perfect addition to add fragrance and light to your nighttime garden.
Fill In The Blanks
Throughout the gardening season, flowers and veggies mature and finish their growth cycle.
When this happens, quick growing, adaptable Alyssum can be plugged into their slots to fill in the blanks and add color, fragrance and pollinator appeal for the remainder of the growing season.
Cover Vast Expanses
If you have a large, open area that needs more visual appeal, there is no better choice as a mass planting or ground cover.
Why Plant Sweet Alyssum?
It’s easy to see why Sweet Alyssum is one of the most popular garden flowers across North America.
With their rugged and versatile beauty and their copious, fragrant blossoms, they make a superb addition to any garden setting.
Easy-to-grow, Sweet Alyssum is a useful, decorative plant that is aesthetically pleasing and also has many practical purposes in the garden.
As a cover crop, it attracts pollinators like butterflies. As a living mulch, it smothers weeds, helps retain moisture and ultimately helps all the plants around it thrive.
When you include Alyssum in your spring and summer flower beds, you can always count on having something colorful and pretty to enjoy.
The tiny flowers are rugged and persistent and will continue to delight throughout the season as long as you keep them deadheaded.
Even when other flowers are beaten down by hard rain, you can count on these sturdy troopers to continue rearing their pretty little heads.