Allium bulbs are planted in fall so they can chill over winter and bloom the following late spring. They ask for very little once in the ground.
Planting
- Unpack right away. Open the bag when it arrives and store bulbs in a cool, dry, dark spot until planting time.
- Plant in fall. Get bulbs in the ground a few weeks before the soil freezes so roots can establish.
- Pick a sunny spot. Full sun produces the tallest stems and largest globes, though the bulbs tolerate part shade.
- Check drainage. Alliums rot in soggy ground; amend heavy clay with compost or plant in a raised bed.
- Set depth and spacing. Plant about 6 in. deep with the pointed end up, spacing bulbs 6-9 in. apart. Groups of five or more look best.
- Water in. Soak the area once after planting to settle the soil around the bulbs.
Watering
- Keep it light. Natural rainfall is usually enough; water only during extended dry spells in spring.
- Stop after bloom. Let the soil dry as foliage yellows so bulbs can go dormant cleanly.
Feeding
- Feed in fall. Mix a balanced bulb fertilizer or bone meal into the planting hole.
- Top up in spring. Scatter a light application of balanced fertilizer as shoots emerge.
Pruning & Aftercare
- Leave the leaves. Allow foliage to yellow and die back naturally to recharge the bulb for next year.
- Deadhead or dry. Cut spent globes for dried arrangements, or leave them standing for late-season structure.
- Mulch in cold zones. A 2 in. mulch layer helps moderate winter freeze and thaw cycles.
Containers
- Use a deep pot. Choose a container at least 12 in. deep with drainage holes and well-draining potting mix.
- Protect in winter. In zones 3-5, move pots to an unheated garage or shed so bulbs still get cold but avoid deep freezing.