Alliums, planted during fall to ensure beautiful blooms come spring, add a spectacular and architectural dimension to the garden. There are hundreds of varieties, including the onions and garlic we eat. The ornamental varieties often have round, onion-like flower heads and leaves similar to onions.
However, there are varieties with star-like clusters of flowers and others with hanging pendants of blossoms. Some alliums have dramatic 12-inch flower heads on 6-foot stems.
Watch the video to see Martha planting alliums at her Bedford farm.
Plant Type: bulb
Hardiness Zones: 4-10
Height: 5 to 60 in.
Width: 3 to 12 in.
Bloom Time: varies with variety, but generally late spring through early summer
Plant the bulbs in autumn, for bloom the following season. As a general rule, you should plant the bulbs three times the depth of the bulb itself. Make sure you plant them root end down.
The addition of compost and bone meal to the soil will encourage big, healthy blooms.
Alliums are not prone to many problems, except certain rots if conditions are too wet.
After flowering, heads can be left on the plant to dry. The dried seed heads look attractive in the garden and can be cut for arrangements. Keep foliage watered after flowering, in order to feed the plant.
See Martha's behind-the-scenes allium planting photos at The Martha Blog.