What to plant in May in Wyoming

Last chance in May

Cantaloupe / Muskmelon (start seeds indoors, by May 6) · Cucumber (start seeds indoors, by May 6) · Pumpkin (start seeds indoors, by May 6) · Sunflower (start seeds indoors, by May 6) · Watermelon (start seeds indoors, by May 6) · Winter Squash (start seeds indoors, by May 6) · Zucchini / Summer Squash (start seeds indoors, by May 6) · Green Onion / Scallion (transplant outdoors, by May 2) · Arugula (direct sow (spring), by May 6) · Beet (direct sow (spring), by May 6) · Fava Bean (Broad Bean) (direct sow (spring), by May 6) · Green Onion / Scallion (direct sow (spring), by May 6) · Mizuna (direct sow (spring), by May 6) · Onion (direct sow (spring), by May 6) · Radish (direct sow (spring), by May 6) · Shallot (direct sow (spring), by May 6) · Tatsoi (direct sow (spring), by May 6) · Cabbage (transplant outdoors, by May 9) · Collard Greens (transplant outdoors, by May 9) · Horseradish (plant crowns / divisions, by May 9) · Kale (transplant outdoors, by May 9) · Kohlrabi (transplant outdoors, by May 9) · Onion (transplant outdoors, by May 9) · Rhubarb (plant crowns / divisions, by May 9) · Shallot (transplant outdoors, by May 9) · Carrot (direct sow (spring), by May 13) · Chervil (direct sow (spring), by May 13) · Endive & Escarole (direct sow (spring), by May 13) · Kohlrabi (direct sow (spring), by May 13) · Lettuce (direct sow (spring), by May 13) · Mustard Greens (direct sow (spring), by May 13) · Rapini (Broccoli Raab) (direct sow (spring), by May 13) · Turnip (direct sow (spring), by May 13) · Watercress (direct sow (spring), by May 13) · Asparagus (plant crowns / divisions, by May 16) · Bok Choy / Pak Choi (transplant outdoors, by May 16) · Broccoli (transplant outdoors, by May 16) · Brussels Sprouts (transplant outdoors, by May 16) · Cauliflower (transplant outdoors, by May 16) · Chives (plant crowns / divisions, by May 16) · Endive & Escarole (transplant outdoors, by May 16) · Leek (transplant outdoors, by May 16) · Lettuce (transplant outdoors, by May 16) · Napa Cabbage (transplant outdoors, by May 16) · Parsley (transplant outdoors, by May 16) · Radicchio (transplant outdoors, by May 16) · Sorrel (plant crowns / divisions, by May 16) · Swiss Chard (transplant outdoors, by May 16) · Watercress (transplant outdoors, by May 16)

Sow or plant outdoors in May (118)

Direct sowing and transplanting windows that fall in May, most urgent first. Windows are one-to-two-week bands around the ideal date.

For fall and winter harvests (2)

Sowings counted back from Wyoming's first fall frost, so the crop matures before the cold - or, for garlic and similar, planted after it.

Start seeds indoors in May (7)

Indoor sowings for transplants later. Six to eight weeks under lights is typical for tomatoes and peppers; onions and leeks need longer.

Keep sowing (succession)

Repeat sowings of crops already in the ground, for a steady harvest instead of a glut.

• Pea: sow again on May 9 and May 21
• Spinach: sow again on May 9 and May 21
• Mache (Corn Salad): sow again on May 13 and May 27

Harvesting in May

First harvests expected this month from crops sown or planted on time earlier in the season.

Planting dates for popular crops in Wyoming

Every crop has its own full-year dates for Wyoming: indoor start, transplant or direct sowing, and harvest.

Last-frost month: May garden jobs in Wyoming

1. The average last frost is May 20. Hardy crops can go out now - green onion / scallion, arugula, beet, fava bean (broad bean) - but hold tender ones like tomatoes, peppers and squash until after that date.
2. Start hardening off indoor seedlings 7-10 days before they go out: a few hours of outdoor shade first, building up to full sun and nights outside.
3. Keep row cover or old sheets handy and watch the 10-day forecast - a clear, still night after a warm spell is the classic late-frost setup.
4. Soil temperature matters as much as the calendar: most warm-season seed rots below about 60°F. Check the frost dates guide for how the Wyoming average is worked out.

USDA zone chart for 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.

Questions gardeners ask