When to plant lettuce 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). Lettuce 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 lettuce in Wyoming: the short answer
For a spring planting, plant out Apr 29 – May 16, with seeds started indoors Apr 15 – Apr 29. Seeds germinate in soil from 35 to 80°F.
Succession sow again in Wyoming: May 18 · May 30 · Jun 11 · Jun 23
Spring succession stops before summer heat makes it bolt. Start sowing again in late summer for a fall crop (see the fall window above).
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 lettuce in Wyoming, step by step
- Start seeds indoors (Apr 15 – Apr 29). Sow seeds ⅛ inch deep in seed-starting mix under bright light. They take 2-10 days to sprout, fastest in soil around 65°F. Harden seedlings off for a week before they go outside.
- Prepare the bed. It needs six or more hours of sun for the best growth, though four to six hours in partial shade is enough and loose soil at least 8 inches deep, with a pH between 6.0 and 7.0. Dig in compost before planting.
- Plant out (Apr 29 – May 16). Space plants about 10 inches apart in rows 14 inches apart. It tolerates a light frost but not a hard freeze. As a cool-season crop it does best before summer heat arrives in Wyoming.
- 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, slugs, snails, cutworm. Diseases and disorders: downy mildew, bottom rot, tipburn (calcium disorder).
- Harvest (from about Jun 5 – Jul 5). Lettuce takes 30-60 days to reach harvest. Seed needs light - barely cover it. Will not germinate above ~80 F soil. Loose-leaf types give the fastest, most forgiving cut-and-come-again harvest.
Figures come from our crop data; dates use Wyoming’s average frost dates. More in the full lettuce growing guide.
Lettuce 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 lettuce dates shift with them.
When to plant lettuce in nearby states
Questions gardeners in Wyoming ask
When is the best time to plant lettuce in Wyoming?
Plant lettuce transplants outdoors in Wyoming between April 29 and May 16. 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 lettuce seeds indoors in Wyoming?
Start seeds indoors between April 15 and April 29, about 4 weeks before the last frost, so the seedlings are ready to plant out from April 29.
Can I plant lettuce in the fall in Wyoming?
Yes. For a fall crop, sow between July 11 and July 28, so the crop matures in cool weather before Wyoming's first frost around September 15.
When will lettuce planted in Wyoming be ready to harvest?
Planted on time, lettuce is usually ready from about June 5 to July 5, 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.