How to Grow Sweet Alyssum

Written by Dr. Joseph Mercola Fact Checked

sweet alyssum

Story at-a-glance -

  • Sweet Alyssum are disease-resistant and easily started from seed in your garden, or indoors six weeks before the first frost; plant in full sun in cooler climates but with some afternoon shade in warmer climates
  • There are several drought- and heat-resistant varieties, offering blooms through most of the summer; they may bloom a second time if trimmed back by one-third
  • The leaves and flowers are added to salads for a unique peppery flavor. Traditionally, the plant has also been used to treat conditions such as rabies, edema and dental pain due to cavities
  • Strong companion plants include the Dahlia David Howard, Giant Hyssop and Sedum Herbstfreude, also known as Autumn Joy. Consider using an app to plan your garden, take seasonal notes and share your photos and garden information with friends

Flowers are more than just a pretty way to fill your garden. Apart from their aesthetic quality, they have the power to reduce stress and inspire creative thinking. You might even find yourself less anxious while admiring your garden.

Flowers are often given as gifts to friends and loved ones and many have natural scents when in bloom, providing you with a natural air freshener and room deodorizer. Some flowers, such as marigolds, are natural pest repellents for your garden.1 Others play an important role in the growth of more flowers, fruits and vegetables by attracting pollinators such as bees, butterflies and wasps.

A study published in Evolutionary Psychology from Rutgers University2 revealed flowers help to improve emotional health by improving feelings of life satisfaction and positive social behavior. Female participants in the study reported those positive feelings lasted for days.

In the same study, those who gave the flowers were perceived as happy, achieving and capable individuals who were more emotionally intelligent and appreciative of beauty and nature.3

In addition to brightening up a room, some flowers may also be used in tea or taken medicinally when used properly, such as rose, chamomile, evening primrose and pagoda flower.4 However, while Sweet Alyssum is beautiful in your landscape and may be tasty in your salad, it is not often used medicinally.5

History of Sweet Alyssum

Sweet Alyssum, (Lobularia maritima), also known as Sweet Alison, is indigenous to the Mediterranean region, including the Canary Islands and the Azores, growing along the coast in areas of full sun. A member of the mustard family, it is often added to salads in Spain for a vitamin C boost. Although some eat Sweet Alyssum, others may get a rash from handling it.6

The name alyssum is derived from the Greek language. Since the prefix "a-" negates the word following it and "lyssa" means rage, alyssa means "without rage."7 Those who named the flower may have had rabies in mind as it was used in folk medicine to treat the condition. In the language of flowers, Sweet Alyssum means "worth beyond beauty" or "sweetness of soul."8

Alyssum was found in gardens as far back as the 1500s and prized for their low forming growth and fragrant flowers. During the 1800s, the yellow variety enjoy popularity in the U.S. By the 1900s, the more fragrant white flowered variety grew in popularity and was recommended as a plant for attracting bees.9

Sweet Alyssum Is Best Known for White Flowers

The genus alyssum contains nearly 170 species of flowering plants in the Brassicaceae family. Most are annual or perennial herbaceous plants growing up to 100 cm (nearly 4 inches) high with yellow or white flowers. Although Sweet Alyssum is best known for the fragrant white-flowered type, the plant does come in a variety of other colors as shown in this short video, including:10

  • Easter Bonnet — This is an early blooming variety in lavender or white, blooming through the spring
  • Pastel Carpet — This is a blend of pink, lavender and cream colors, offering a subdued colorful variety to your garden
  • Snow Princess — This is a sterile hybrid with white flowers. It is extremely heat tolerant and noted for the characteristic of spreading and cascading
  • Blushing Princess — This has a fragrant flower and a lavender color, also heat tolerant growing up to 8 inches tall and spreading nearly 24 inches wide
  • Wonderland series — This type has a deep red color growing in a compact flat plant, excellent for edging as it only reaches up to 5 inches tall and spreads 24 inches across

Sweet Alyssum is a delicate carpet of tiny flowers with narrow lance-shaped leaves and flowers with tiny four-petal, cross shapes. Although an annual plant in many hardiness zones, those who live in areas with a mild winter may find they return easily as a perennial, or even bloom through the winter.

The plants easily self-seed, being carried by the wind through your yard. If you're planning to change varieties the following summer you may be surprised by several volunteers sprinkled throughout your garden.11

Planting and Caring for Your Hardy Annual Sweet Alyssum Flower

Alyssum prefers a rich soil with a neutral pH. They're easily started from seed and since they enjoy the cool weather, they can be sown directly into your garden several weeks before the last frost.12 Gardeners in the U.S. Department of Agriculture Hardiness Zones 7 through-1113 may have plants growing year-round.14

As long as it's not a hard freeze, your seeds will germinate and grow outdoors. However, if you'd like a large impact on your garden, start the seeds indoors five to six weeks before your last expected frost date.

Sowing seeds is done simply by scattering them on the ground and pressing down so they make good contact with the soil and aren't blown away. It is important the seeds are still exposed to light in order to germinate. Keep the soil moist until germination and then water whenever the soil feels dry. If you start indoors, don't transplant outside until after the danger of frost is past.15

Although it is somewhat frost tolerant once established, tender transplants do not fare well. In northern climates where the summers are cooler, the plants will enjoy full sunlight. However, in warmer climates, as you move further south, the plants need protection from the hot afternoon sun. This will extend blooming a little longer into the season.16

It requires a significant amount of energy for the plants to produce so many flowers. Once the weather gets very hot, Alyssum will stop blooming. The more heat- and drought-resistant plants may bloom longer into the hot weather.

Deadheading the plants will help them continue to bloom. This can sometimes be tedious if you have a large bed. With a large drift, you can shear them by one-third, encouraging the plants to set new buds quickly.

When planted in the ground, you may not need to add fertilizer unless the soil is poor. Planted in a container, alyssum will need more frequent watering and monthly feedings with an organic fertilizer. Alyssum makes a carpet-like ground cover that spreads and can create a living mulch under taller plants. They work well to fill in nooks and crannies on walkways and walls or along edges.17

Traditional Uses of Sweet Alyssum

Today, Alyssum is added to salads for flavor. However, there is a long list of traditional uses, some of which are not in current practice as the condition it was used to treat responds more consistently to other treatments. Rabies is one such example. Before using Alyssum for any health condition, consult with a knowledgeable practitioner and use it in moderate amounts.

Individuals who are allergic should avoid it entirely. That said, young leaves, flowers and stems can add flavor to your salad and other dishes, and the plant is commonly used in Spain as an astringent in the treatment of gonorrhea, and as a diuretic.18 Alyssum has also been used to treat:19

Abdominal pain

Colds and coughs

Pain from cavities and bleeding gums

Edema

Ascites (fluid in the abdomen)

Scurvy

Sweet Alyssum Helps Get Rid of Pests Naturally

Sweet Alyssum attract pollinators and butterflies,20 and are generally pest free. Occasionally, aphids can create a problem, especially when the plants are under stress. These are tiny insects known to pierce the stems of tender shoots and suck out nutrient-rich sap. Although an infestation may start out slowly, aphids reproduce quickly and a colony can easily destroy your garden if left untreated.

For minor infestations it might be possible to physically remove the insects using a pair of gardening gloves and a brush or pinch them off the plant. If the infestation is contained on one or two stalks, it is wise to prune off the affected portion, drop it in a bucket of soapy water and dispose of the plant material.21

If you have more bugs, it might be possible to use water pressure with the simple application of a garden hose. Make sure your plants are well-established and older as the pressure may harm younger, more fragile plants. The basic nature of mild household detergents makes it perfect to get rid of a mild or moderate aphid infestation.

Dilute a few tablespoons of dish soap and a bucket of lukewarm water and use a spray bottle or sponge to apply it to the plants where the aphids have taken hold. The soap dissolves the waxy coating from the aphid's body, which dehydrates the insect and eventually kills them without harming the plants.22

A cocktail of equal parts thyme, peppermint, clove and rosemary essential oils mixed in a small spray bottle of water is a potent insecticide against both the pest and their eggs and larvae.

Anytime you're treating for aphids, whether you're removing them manually using a garden hose or spraying on soapy water, make sure you treat the underside of the leaves where the eggs and larvae may be hiding.23

Planning Your Garden

Alyssum does well in borders or planted along a rock or stone wall. You may consider planting it to fill in gaps in your garden or as a living mulch around your trees. However, if these beautiful ground-covering flowers are part of a larger garden scheme, you may want to consider the following as companion plants:

Blue Fortune (Giant Hyssop) — This drought- and heat-tolerant plant is generally disease- and pest-free. It displays lavender blue spikes from midsummer to early fall and is deer tolerant and low maintenance. When crushed, the aromatic foliage has an anise scent and can be used to flavor cold drinks.24

Dahlia "David Howard" — These apricot orange flowers are set against dark purplish foliage. The flowers bloom massively from July until the first frost. They work well along borders and in containers and have a long vase life as cut flowers. Hardiness zones 3 through 7 may need to dig the Dahlia tubers in the fall before the first frost and store them over the winter to protect the plants.25

Sedum Herbstfreude (Autumn Joy) — This vigorous flowering plant lasts more than six months and will remain attractive through the winter months in warmer climates. It stands 2 feet tall and wide, topped with tiny, starlight raspberry pink flowers that change to rich rose and copper rust in the fall.

They are best grown in full sun, but tolerate light shade and are attractive to bees, hummingbirds and butterflies. The plants are low maintenance, deer- and drought-resistant and heat tolerant.26

There are multiple health benefits to gardening, including improved emotional and mental health, cardiovascular exercise, stress relief, improved hand strength and dexterity and reduced risk of Alzheimer's disease.27 If you want to give it a try, the following apps may make quick and easy work out of planning your garden space.

  • Gardenize — This app allows you to choose your plants, upload your photos and take notes on your garden plan and growth. It's also a social platform where you can share your information with friends and ask questions of others.
  • Home Design 3D Outdoors — The free version allows you to make your plans but not save the information. Using an intuitive interface, the app shows your plan in 3D and allows you to edit your dimensions and add plants and lawn furniture.
  • Small Garden Ideas — This app helps you organize a small garden space, including an indoor garden or patio garden. Also included are ideas for vertical gardens, winter gardens and information on how to maintain your flowers and plants.