Alliums can be propagated by dividing the bulbs or by collecting and sowing the seeds.
Dividing the bulbs
- Dig up the plant in the fall or early spring
- Separate the bulbs along the visible lines of division
- Replant the healthy bulbs in the original space and the remaining bulbs in other areas of the garden
Collecting and sowing the seeds
- Wait for the seedhead to dry
- Collect the seeds
- Sow the seeds immediately or store them for spring
- Sow the seeds directly in the garden in the spring or summer
- Start the seeds indoors to speed up germination
Tips for propagating alliums
Bulbs start to multiply after a couple of years, so it’s a good idea to refresh a clump every 3–4 years
Hybrids won’t be true to the parent plant It can take several years for alliums grown from seed to reach flowering size Seeds should be sown while they are fresh and ripe You can use a knife or saw to split the bulbs