How to Grow Sweet Alyssum (Lobularia maritima)

Last Updated on June 12, 2023 by Real Men Sow

Sweet Alyssum (Lobularia maritima) is a small, colorful flower that can be used to cover your garden and landscape. The low-growing, European-native foliage quickly grows and covers the ground in tiny, cross-shaped, four-petal flowers. This happens within just two months of the seed being sown. Its gray-green, lance-shaped, slightly hairy leaves are narrow and narrow.

Sweet alyssum, which can be grown from seeds or plants, is a cool-season plant that can be planted in spring after all danger of frost has passed. In frost-free areas, sweet alyssum can also grow through the winter and fall. 

Planting Sweet Alyssum (Lobularia maritima)

Sweet Alyssum (Lobularia maritima) can be sown from early spring through early summer and autumn, where winters are mild. Alyssum blooms quickly and stops flowering in hot conditions. Spread the seeds in cultivated soil or containers 2 inches (5 cm) apart. Cover them lightly with soil. If the seedlings have four or more leaves, you should thin them to 6 inches (15 cm) in all directions.

Propagating Sweet Alyssum (Lobularia maritima)

This fast-growing plant is best grown in spring. It can be started from seeds. The seeds can be started indoors before the last frost, and then transplanted outdoors once the danger of frost has passed. Although Alyssum can be frost-tolerant once it is established, tender transplants are not frost-resistant.

You can also direct sow seeds outdoors once the soil is thawed. This plant can be used as an edger or filler plant. It can fill in any empty spots in the soil, and it is also a good choice for filling in gaps between other plants. This carpet-forming, the low-growing plant cannot be propagated using any other methods.

Growing Sweet Alyssum (Lobularia maritima) From Seed

Sweet Alyssum (Lobularia maritima) can be grown from seeds or transplanted directly from nursery boxes. Both options are readily available. Start with seeds by placing the seeds on top of the soil. Then, press the seeds down lightly so that they are in contact with the soil. The soil should be kept moist until germination. Water the soil if it feels dry.

General Care Guide for Sweet Alyssum (Lobularia maritima)


Sweet Alyssum (Lobularia maritima) is happy in full sun but does not like long periods of dryness. This plant will thrive in areas that are hot and dry. Your sweet alyssum should be planted somewhere that receives six to eight hours of sun per day.


Sweet alyssum prefers soil that is well-drained and moist. They can be found in many locations, including sandy beaches and dunes. It can grow on slopes and walls, as well as cracks in sidewalks and walls. It will not thrive in soil that is too wet or with poor drainage.


Sweet alyssum plants need at least one inch of water each week. They should be watered more often during dry spells or hot weather. Water should drain well. You should add water if you plant sweet alyssum on a stony or dry landscape.

Temperature and Humidity

Sweet Alyssum (Lobularia maritima) can be grown in mild weather throughout the year, but it is very hardy. They are usually self-seeders and can be very vigorous. However, hybrid varieties might not look the same as their parents. It may appear that the same plants have survived all year, but the truth is that new seedlings are emerging.

Sweet alyssum plants can still bloom, even though some varieties might stop flowering due to heat. They will likely re-bloom in the fall. You can compensate for high humidity by decreasing the water that is given to plants.


In-ground sweet alyssum plants don’t usually require fertilizer unless the soil is very poor. Container plants will require monthly fertilization with a well-balanced, water-soluble fertilizer. Add a time-release fertilizer when you plant seeds. After the blooms have finished, fertilize again to encourage new growth. Too much fertilizer can result in lush foliage and fewer blooms.


Sweet alyssum can be deadheaded to keep them flowering and make new buds quickly. Shearing plants by one-third is a better option than deadheading if you have large numbers. Some varieties are easy to reseed. Pruning will help keep your plants neat and tidy.

Companion Planting

Alyssum comes in pastel or white colors and is a great little flower to put in the corners of your beds. You can also grow it under tall vegetables or among herbs. Alyssum attracts beneficial insects and tiny wasps.

Pests & Plant Diseases of Sweet Alyssum (Lobularia maritima)

Poorly draining soil can cause downy mildew, crown and stem rot, and a general decline in sweet alyssum. These plants should not be overwatered. Sweet alyssum is a favorite of songbirds, butterflies, and pollinators. However, they can also be at risk from other diseases and pests.

Common Problems With Sweet Alyssum (Lobularia maritima)

The plant can thrive in warmer climates and will spread easily. It can be difficult to grow outside these areas. These conditions include high heat index, freezing temperatures, poor drainage, poor soil, or insufficient light.

Wilting Flowers and Foliage

It could wilt if you don’t plant alyssum with well-drained soil, or if the temperature is very high. Alyssum is not able to withstand extreme heat. While some cultivars can withstand high temperatures without wilting (the most common ones will shrink in the heat of summer), others have been designed to withstand them. The heat can be counterbalanced with water. However, ensure that the soil drains well.

The bottom line is that you should expect some wilting. When the temperature drops, it may recover in the fall. To encourage new growth, you can cut the wilted plants by one-third and water them.

Curling Flowers and Leaves

You can find mini sap-sucking mites under flower petals and leaves if you notice curled flowers or foliage. If you have a magnifying lens, they will appear as tiny oval spiders to the naked eye. To get rid of them, you can use neem oil and insecticidal soap.

Yellowing Leaves

A spike in temperature can cause your plant’s leaves to turn yellow. A plant’s leaves turning yellow is a sign that it is in danger of dying. A yellow leaf, or several leaves, is a warning sign but not necessarily a death sentence.

Find the root cause of the problem and fix it. The entire plant will wilt if it is not able to produce flowers or foliage. You can then cut the plant back and wait for sweet alyssum growth in more temperate environments or better growing conditions.

Real Men Sow
Real Men Sow

Hello, I’m Pete and I’m currently based in the west of Scotland, in a small place called Rosneath, where I’m exploring my garden adventures. I personally started gardening around 6 years ago and initially, I started out by growing my favorite fruits and berries, such as strawberries, Raspberries & Gooseberries. Since then I’ve added a lot of vegetables and working closely with my neighbor, it’s been a lot of fun.