When to Plant Alliums in Oklahoma
Ornamental alliums (Allium spp.) bridge the gap between spring and summer with their striking globe-shaped flower heads in shades of purple, violet, white, and pink. Blooming after tulips have faded, they extend the spring display well into early summer. 'Gladiator', 'Globemaster', and 'Purple Sensation' produce softball-sized heads on 18–36 inch stems, while smaller species create charming accents at border fronts. Deer and rodents shun them completely due to the characteristic onion scent. Dried seed heads provide architectural interest into fall.
Oklahoma spans USDA hardiness zones 6b, 7a, 7b, 8a (with planting data available), so planting dates vary by your location within the state. Click your zone below for the most accurate dates.
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Click your county for exact Alliums planting dates based on your local frost dates.
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Alliums Planting Calendar for Oklahoma
▸ Zone 6b ~205 day growing season · Full guide →
Last frost: April 3 · First frost: October 25 · 205 day season
| Activity | When | Date Range |
|---|---|---|
| Bloom | October 11 | Oct 11 – Nov 8 |
| Fall Sowing | September 13 | Sep 13 – Sep 27 |
▸ Zone 7a ~221 day growing season · Full guide →
Last frost: March 25 · First frost: November 1 · 221 day season
| Activity | When | Date Range |
|---|---|---|
| Bloom | October 25 | Oct 25 – Nov 15 |
| Fall Sowing | September 27 | Sep 27 – Oct 11 |
▸ Zone 7b ~235 day growing season · Full guide →
Last frost: March 18 · First frost: November 8 · 235 day season
| Activity | When | Date Range |
|---|---|---|
| Bloom | November 1 | Nov 1 – Nov 22 |
| Fall Sowing | October 4 | Oct 4 – Oct 18 |
▸ Zone 8a ~255 day growing season · Full guide →
Last frost: March 8 · First frost: November 18 · 255 day season
| Activity | When | Date Range |
|---|---|---|
| Bloom | November 11 | Nov 11 – Dec 2 |
| Fall Sowing | October 14 | Oct 14 – Oct 28 |
Growing Tips for Oklahoma
Plant bulbs in fall, 3–4 times as deep as the bulb diameter (typically 4–6 inches for large types, 3 inches for small species). Space 6–8 inches apart for standard cultivars. Foliage often looks untidy as it dies back before bloom — plant around perennials that will conceal the yellowing leaves. Excellent drainage is essential; alliums rot in wet soils. Leave bulbs in place for naturalization; divide every 3–4 years when clusters become congested. Deadhead spent globes or leave for ornamental seedheads and self-sowing.
Alliums in Other States
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Frequently Asked Questions
When should I plant Alliums in Oklahoma?
Planting dates for Alliums in Oklahoma depend on your USDA zone. Oklahoma spans zones 6b, 7a, 7b, 8a. Check the planting calendar above for your specific zone's frost dates and planting windows.
What zone is Oklahoma for planting?
Oklahoma contains USDA hardiness zones 6b, 7a, 7b, 8a. Your specific zone depends on your location within the state — northern and higher-elevation areas are in colder zones, while southern and coastal areas are warmer.