When to plant onions in West Virginia
West Virginia’s average last spring frost is May 5, and the first fall frost typically arrives around October 5 — about 153 frost-free days (USDA zones 5b, 6a, 6b, 7a). Onion needs 90–120 days to mature, which fits comfortably within West Virginia's growing season.
When to plant onions in West Virginia: the short answer
For a spring planting, plant out Apr 7 – Apr 24, with seeds started indoors Feb 17 – Mar 3. Seeds germinate in soil from 40 to 90°F.
Windows are ~1–2 week bands around each date. Frost dates are a statewide average from NOAA/NCEI normals; your town may differ by two weeks or more. Calendar year 2026.
How to grow onions in West Virginia, step by step
- Start seeds indoors (Feb 17 – Mar 3). Sow seeds ½ inch deep in seed-starting mix under bright light. They take 7-14 days to sprout, fastest in soil around 70°F. Harden seedlings off for a week before they go outside.
- Prepare the bed. They need at least six to eight hours of direct sun a day and loose soil at least 12 inches deep, with a pH between 6.0 and 7.0. Dig in compost before planting.
- Plant out (Apr 7 – Apr 24). Space plants about 4 inches apart in rows 12 inches apart. It handles frost well, so it can go out before the last frost date. As a cool-season crop it does best before summer heat arrives in West Virginia.
- Water and feed. Give it steady, even moisture, about an inch of water a week from rain or the hose.
- Watch for pests and problems. Pests: onion maggot, onion thrips. Diseases and disorders: downy mildew, white rot, neck rot, purple blotch.
- Harvest (from about Jul 13 – Aug 12). Onion takes 90-120 days to reach harvest. Match the day-length type to your latitude: long-day onions for the north, short-day for the south, day-neutral anywhere. Bulbing is triggered by day length, not calendar date.
Figures come from our crop data; dates use West Virginia’s average frost dates. More in the full onion growing guide.
Onion planting dates by USDA zone in West Virginia
West Virginia spans USDA zones 5b, 6a, 6b, 7a. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average, so the onion dates shift with them.
When to plant onions in nearby states
| State | Last frost | Plant out |
|---|---|---|
| West Virginia (this page) | May 5 | Apr 7 – Apr 24 |
| New Jersey | April 20 | Mar 23 – Apr 9 |
| Pennsylvania | May 1 | Apr 3 – Apr 20 |
| Delaware | April 14 | Mar 17 – Apr 3 |
| Maryland | April 14 | Mar 17 – Apr 3 |
| District of Columbia | April 10 | Mar 13 – Mar 30 |
| Virginia | April 15 | Mar 18 – Apr 4 |
Questions gardeners in West Virginia ask
When is the best time to plant onions in West Virginia?
Plant onion transplants outdoors in West Virginia between April 7 and April 24. That timing is set by West Virginia's average last spring frost of May 5.
When should I start onion seeds indoors in West Virginia?
Start seeds indoors between February 17 and March 3, about 10 weeks before the last frost, so the seedlings are ready to plant out from April 7.
When will onions planted in West Virginia be ready to harvest?
Planted on time, onions are usually ready from about July 13 to August 12, 90-120 days after transplanting.
When is the last frost in West Virginia?
On average around May 5, with the first fall frost around October 5 - about 153 frost-free days. Your town may differ by two weeks or more.