When to plant basil in Wyoming
Wyoming’s average last spring frost is May 20, and the first fall frost typically arrives around September 15 — about 118 frost-free days (USDA zones 3a, 3b, 4a, 4b, 5a, 6a). Basil needs 30–60 days to mature, which fits comfortably within Wyoming's growing season.
Wyoming covers a wide range of climates, so your exact frost dates may differ from the state average by two weeks or more. For dates tuned to your town, use the calendar generator.
When to plant basil in Wyoming: the short answer
For a spring planting, plant out May 27 – Jun 13, with seeds started indoors Apr 8 – Apr 22. Wait until the soil is at least 65°F and frost is over.
Succession sow again in Wyoming: Jun 24 · Jul 15
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 basil in Wyoming, step by step
- Start seeds indoors (Apr 8 – Apr 22). Sow seeds ⅛ inch deep in seed-starting mix under bright light. They take 5-10 days to sprout, fastest in soil around 80°F. Harden seedlings off for a week before they go outside.
- Prepare the bed. It needs at least six to eight hours of direct sun a day and loose soil at least 10 inches deep, with a pH between 6.0 and 7.0. Dig in compost before planting.
- Plant out (May 27 – Jun 13). Space plants about 10 inches apart in rows 12 inches apart. It is killed by frost, so nothing goes outside until the danger has passed.
- 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: aphids, Japanese beetle, slugs. Diseases and disorders: basil downy mildew, fusarium wilt, damping off.
- Harvest (from about Jul 3 – Aug 2). Basil takes 30-60 days to reach harvest. Cold soil stalls it - wait for warm nights. Pinch above a leaf pair every couple of weeks and remove flower buds to keep leaves coming. Downy mildew-resistant varieties are worth seeking out.
Figures come from our crop data; dates use Wyoming’s average frost dates. More in the full basil growing guide.
Basil planting dates by USDA zone in Wyoming
Wyoming spans USDA zones 3a, 3b, 4a, 4b, 5a, 6a. 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 basil dates shift with them.
When to plant basil in nearby states
Questions gardeners in Wyoming ask
When is the best time to plant basil in Wyoming?
Plant basil transplants outdoors in Wyoming between May 27 and June 13. That timing is set by Wyoming's average last spring frost of May 20; Wyoming spans several climates, so cooler and higher parts of the state run later.
When should I start basil seeds indoors in Wyoming?
Start seeds indoors between April 8 and April 22, about 5 weeks before the last frost, so the seedlings are ready to plant out from May 27.
What is the latest I can plant basil in Wyoming?
About August 16. Basil needs at least 30 days to mature, and frost around September 15 ends the season, so later plantings risk being cut short.
When will basil planted in Wyoming be ready to harvest?
Planted on time, basil is usually ready from about July 3 to August 2, 30-60 days after planting.
When is the last frost in Wyoming?
On average around May 20, with the first fall frost around September 15 - about 118 frost-free days. Your town may differ by two weeks or more.