Allium, or Ornamental Onion, is a hardy perennial bulb. There are multiple forms grown for their attractive flowers in garden borders, as specimen plants, and for cut and dry flowers. Their starry “fireworks” flower umbels are often large and provide color and attraction on plants ranging from dwarf to tall. The plants will flower in late spring or early summer. Most are hardy in zones 4 to 8.
8 Tips For Planting & Caring For Allium
Allium bulbs are usually planted in fall, but some types can be spring planted.
Depth & Spacing
Place the bulbs pointed end up, planting small bulbs 3 to 5 inches deep and large bulbs 6 to 8 inches deep. Space the bulbs at least as far apart as the diameter of the flowers.
Watering & Soil
Alliums are low-maintenance, easy-to-grow plants that are drought-tolerant and require well-drained soil.
They tolerate light shade, but stems may need support in shady conditions.
Ornamental onions are moderate feeders and benefit from fertilization once a year in spring when growth resumes. Espoma Bulb-Tone (3-5-3), an organic fertilizer, is a good fertilizer for bulbs.
John & Bob’s Soil Optimizer can be used as an amendment to improve the soil. Raised beds can improve drainage, as can amending soil with organic matter.
Pests & Diseases
Ornamental Onions are generally free from pest and disease problems. Deer and rodents do not eat the bulbs. Thrips will sometimes feed on the leaves and flowers. Thrips can be controlled with insecticidal soap or neem oil.
After the plants flower, do not remove leaves until they naturally die. This allows bulbs to “recharge” with nutrients for overwintering.
What Flowers Grow Well With Allium?
Alliums Are Great For Pollinators
Ornamental Allium is related to chives, garlic, and edible onions. The flowers are attractive to beneficial pollinating insects and the onion scent of the plants can help to repel pests from other plants growing nearby.
Other Recommended Reading
- Fall Bulb Planting Tips
- 9 New Bulbs To Plant In Fall – Best Bulbs For Spring Flowers
- 24 Flowers, Fruit, & Plants Perfect For Your Patriotic Garden
- 15 Best Plants For Pollinators
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