How to grow Alyssum in Australia
Sweet alyssum (Lobularia maritima) is a low, honey-scented annual that covers itself in tiny white, pink or purple flowers for months. It is easy from seed, and in the vegie patch it does a useful job: its small flowers feed hoverflies and tiny parasitic wasps, whose young eat aphids.
📖 Our full guide: How to Grow Alyssum in Australia
At a glance
When to sow by region
| Region | When to sow | Regional note |
|---|---|---|
| South East Queensland | March to October | |
| Northern Rivers NSW | March to October | |
| Sydney & Coastal NSW | March to October | |
| Melbourne & Victoria | March to October | Frost-tolerant; sow Mar to Oct in Melbourne. Longer season than SEQ. |
| Adelaide & SA | March to October | |
| Perth & WA | March to October | |
| Tasmania | March and April, September to November | Sow Sep to Nov or Mar to Apr. Hardy and easy. |
| Canberra & ACT | March to October | Alyssum is frost-hardy annual; sow spring or autumn; blooms most of year in cool Canberra; small delicate flowers. |
| North Queensland | May to October | Dry season May to Oct. Alyssum prefers cooler months. |
| Darwin & Top End | May to October | Dry season May to Oct. Alyssum prefers cooler months. |
Where to plant
Alyssum grows in full sun or part shade in almost any soil that drains freely. It does not need rich soil or fertiliser. Use it as an edging along vegie beds, between rows, under fruit trees, between paving or spilling from pots.
It prefers the cooler months. In hot, humid summers plants often stop flowering or die back, then return from self-sown seed when the weather cools.
- Melbourne, Canberra, Adelaide, Sydney and Perth: sow from March to October; it tolerates light frost and flowers for much of the year.
- Hobart: sow in autumn (March and April) or spring (September to November).
- South East Queensland and the Northern Rivers: sow from autumn through to early spring.
- North Queensland and Darwin: sow in the dry season, May to October.
How to plant
- Rake the soil fine and water it first.
- Scatter the tiny seed thinly over the surface and press it in with your hand. Do not cover it, as it needs light to germinate.
- Keep the surface just moist with a fine spray until seedlings appear, usually in about 8 to 10 days.
- Thin seedlings, or plant out punnets, about 20 cm apart.
Watering and feeding
Keep the soil moist while seedlings establish, then water moderately; alyssum copes with dry spells once it is growing. No feeding is needed in most beds, and rich soil gives leafy plants with fewer flowers.
Pruning and care through the year
- When the first flush of flowers fades, trim the plants back lightly. They will soon bush out and flower again.
- Let a few plants set seed if you want it to self-sow, and pull unwanted seedlings while they are small.
Flowering
Alyssum starts flowering about 6 to 8 weeks after sowing and keeps going for months if trimmed after each flush. It is grown for its scent and for the insects it feeds rather than for picking.
Growing in pots
Alyssum suits pots, window boxes and hanging baskets, alone or as a frothy edge around herbs and vegetables. A pot 15 cm wide holds a plant; use ordinary potting mix and water when the top of the mix is dry.
Companion planting
Sweet alyssum is one of the best flowers for drawing helpful insects into the vegie patch. Studies have found it attracts and keeps hoverflies, whose larvae eat aphids, and tiny parasitic wasps that lay their eggs in aphids. Being low, it fits between crops without shading them.
Good companions
- Lettuce A low edging that brings in hoverflies, whose larvae eat the aphids that infest lettuce.
- Brassicas Its flowers feed the small wasps that attack aphids and caterpillars on cabbage family crops.
- Beans Draws aphid predators without competing for space.
- Strawberry A low border that brings in pollinators and pest predators.
Pests and diseases
Alyssum is rarely troubled by pests. Downy mildew is the main problem in cool, damp weather.
Alyssum is rarely troubled by pests.
Diseases to watch for
- Downy mildew Yellow patches on the upper leaf with grey-white fuzz underneath in cool, wet weather. Give plants space and water at the base.
Common questions
Should alyssum seed be covered?
No. Alyssum seed needs light to germinate. Scatter it on the surface, press it in firmly and keep it moist with a fine spray.
Does alyssum attract good insects?
Yes. Its small flowers feed hoverflies and tiny parasitic wasps. Hoverfly larvae eat aphids, and the wasps lay their eggs inside aphids, so alyssum is a popular edging for vegetable beds.
Why has my alyssum stopped flowering?
It often stops after the first big flush or in summer heat. Trim the plants back lightly and water them, and they should flower again within a few weeks. It also flowers more on lean soil than on rich, heavily fed soil.
Is alyssum an annual or a perennial?
Sweet alyssum is grown as an annual, though in mild areas plants can live longer and it often self-sows, so it seems to come back every year.
When should I sow alyssum?
In most of southern Australia, sow from autumn to spring. In South East Queensland sow in the cooler months, and in the tropics sow in the dry season. Pick your region at the top of the page for the months.
Does alyssum self-seed?
Yes, readily. Leave a few plants to set seed and new seedlings will come up nearby. Pull the extras while they are small.
Sources we checked: Johnny's Selected Seeds: Alyssum key growing information; University of New Hampshire: Attracting hoverflies for biological pest control; NC State Extension Gardener Plant Toolbox: Lobularia maritima.