Grow Sweet Alyssum from Seed, the Filler Flower You'll Want Everywhere

Sweet Alyssum is a delicate, fragrant plant that will fill space and attract beneficial insects into your garden. There’s no need to buy flats of these from the garden store when you can grow sweet alyssum from seed and fill your garden for less money.

purple Sweet alyssum flowers

I was one of those gardeners who would buy a flat of Sweet Alyssum to fill in spots in my flowerbed. But once I tried starting them from seed and found out how easy it was and how much I could grow, I’ll be growing sweet alyssum from seed from now on.

Sweet alyssum has small, fragrant flowers. It attracts insects that eat aphids, making it the perfect companion plant in flower beds. It also spreads low to the ground, making it perfect for borders and filling in spaces between taller flowers. With sweet alyssum, you can easily create a carpet of flowers to enhance any garden.

Royal Carpet Sweet Alyssum is a popular bedding plant. With one packet of seeds, you can fill your flower beds with this sweet-smelling heirloom. Sweet alyssum attracts butterflies, beneficial pollinators, and hoverflies that eat aphids.

Royal carpet alyssum grows low to the ground and is beautiful along walkways and spilling over flower pots.

This AAS winner will produce delicate, fragrant flowers to enjoy from spring to fall.

How to Grow Alyssum from Seed

Sweet Alyssum is a popular, all-around great flower to add to your garden. Growing Sweet Alyssum from seed is an excellent way to fill your landscape and save money.

You can sow alyssum seeds outdoors or start seeds indoors. Starting seeds indoors 6 to 8 weeks before the last spring frost can lead to earlier blooms.

Sow alyssum seeds by pressing them lightly into moist soil. The seeds need light to germinate, so you don’t need to cover them. Keep the seeds moist until they germinate, which takes five to 14 days.

Alyssum seeds are tiny and hard to space when planting. They will need to be thinned to 6 inches apart to avoid overcrowding.

Seedlings started indoors can be hardened off and placed outdoors before the last spring frost. Alyssum enjoys the cool spring temperatures and will survive a light frost but needs to be protected from freezing.

Sweet alyssum seedlings

Tips for fail-proof alyssum seed germination

  • Sweet alyssum seeds need light to germinate. Gently press seeds into moist soil.

  • Keep soil temperature at 65-75ºF.

  • Use a humidity dome to keep seeds moist until they germinate.

  • Sweet alyssum seeds will germinate in 5 to 14 days.

White Sweet Alyssum Flowers

How to Grow Sweet Alyssum Flowers

Add sweet alyssum to a flower bed, herb, or vegetable garden. This delightful flower will fill in spaces and attract beneficial pollinators. Plant it next to your spring bulbs to fill in as they die back.

There are so many places you can grow this popular bedding flower. It can cascade over walls, flower pots, and hanging baskets. It’s perfect for pollinator gardens, too.


Sweet Alyssum can grow in full sun to partial shade. In cooler climates, it will have more blooms with full sun. It will appreciate some shade from the intense afternoon sun in hotter climates.


Well-draining soil is crucial to avoid root rot. Other than that, sweet alyssum can thrive in average soil.


Consistent moisture is best for blooms and growth, but be careful not to overwater. These adaptable flowers can tolerate more dry soil, but when the soil stays too wet, the roots will rot.


There’s no need to add additional fertilizer. Excess nitrogen will result in leggy plants instead of more flowers. A slow-release, balanced fertilizer can be used when preparing the soil.


As sweet alyssum grows, it can sometimes start looking scraggly. Since this isn’t a flower you cut for bouquets, you might not realize that cutting and deadheading can help encourage more blooms and contain them into compact growth.

The growth will slow down in the hot summer months. This is a good time to cut it back so it will regrow when cooler temperatures return. You can cut from ⅓ up to ½ of the plant.

closeup of purple sweet alyssum flowers

Sweet Alyssum FAQs

How long does it take to grow alyssum from seed?

Sweet alyssum seeds take 5 to 14 days to germinate. After that, it will take about 45 days for them to start blooming.

Will alyssum come back every year?

It can self-seed to return. In mild climates, it will grow through winter. Eventually, alyssum grows sparse and needs to be reseeded.

Does alyssum like sun or shade?

Sweet alyssum can grow in full sun to partial shade. It goes dormant when temperatures get too hot, so partial shade is usually best in warm summers.

Does alyssum need cold stratification?

No special prep is needed to germinate alyssum, but they need light, so only gently press them into the soil.

Will sweet alyssum come back next year?

Sweet alyssum is an annual and will die in freezing weather. However, you can allow it to self-sow from seeds that develop.

Sweet alyssum is safe for pets and people and is deer-resistant, which adds to its popularity as a bedding flower.

Start growing sweet alyssum from seed. You’ll see how easy it is to fill a flowerbed with the delicate fragrance and attract more butterflies and bees.

Written by Beverly Laudie

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