How to Plant Allium

Plant allium bulbs in fall in full sun. Big globe types go 6–8 inches deep and 12–18 inches apart, and small types 3–4 inches deep and 6–8 inches apart.

How to Plant Allium
When to plant
Fall, around October
Depth
6–8 inches for large bulbs; 3–4 inches for small bulbs
Spacing
12–18 inches apart for large bulbs; 6–8 inches for small bulbs
Sun
Full sun for the best flowers; part shade makes stems lean
Water
Moist but never soggy; bulbs rot in wet ground
Soil
Well-drained

Step by step

  1. Choose a spot in full sun with soil that drains well. In shade, allium stems stretch and the flower heads droop.
  2. For large bulbs such as Globemaster, Gladiator and giganteum types, dig each hole 6–8 inches deep. For small bulbs, 3–4 inches is enough.
  3. Set each bulb with the pointed end up.
  4. Space large bulbs 12–18 inches apart and small bulbs 6–8 inches apart.
  5. Cover, firm the soil, and water in well.
  6. Plant alliums among perennials that fill in by early summer, such as catmint, hardy geraniums or daylilies. Their foliage will hide the allium leaves as they fade.

After bloom

Leave the foliage until it has turned completely brown, even though many alliums start yellowing before the flowers finish; it's still feeding the bulb. Some types reseed heavily, so deadhead those as soon as the flowers fade if you don't want seedlings. Others leave dried seed heads that look good well into summer. Bulbs spread by offsets; separate and replant them in autumn.
Shop all allium →