May is the main planting kickoff in cold-winter zones, when gardens finally move from starts and prep into full outdoor action. Early May often still favors hardy transplants and direct-sown cool-season crops, while mid-to-late May is when many areas can safely set out warm-season plants as frost risk drops. Keep hardening off seedlings, use row cover if nights run cold, and focus on steady watering and early weed control so young plants establish quickly.
Indoors (fresh harvests):
- Microgreens: peas, broccoli, sunflowers, arugula
- Sprouts: alfalfa, broccoli, radish, mung
- Herbs & greens under lights: chives, parsley, mint
Crops to start indoors in good light: tomato, pepper, eggplant, basil, cucumber, squash, melons, zinnia, marigold
Transplants to move outdoors (harden first): broccoli, cabbage, cauliflower, kohlrabi, lettuce, onion, parsley, pansies, snapdragons — and by mid-to-late May, tomato, pepper, and eggplant as frost risk drops
Crops that can be directly sown outdoors in May: peas, spinach, kale, Swiss chard, beets, carrots, radishes, turnips, parsnip, dill, cilantro — and after last frost: beans, corn, cucumber, squash, sunflower, nasturtium, sweet peas
Cover crops: oats, field peas, hairy vetch, red clover
Tip: This zone group covers a lot of territory. Nothing replaces talking with experienced gardeners in your area and watching the weather closely.
Use your USDA zone as a guide. Microclimates matter — coastal/urban spots run warmer; high elevation runs colder.
