Cold Winter Areas

Zones: 1–7a

These zones experience cold winters with extended periods of freezing temperatures. In March, monitor soil conditions, thaw cycles, and late frosts as you prepare for early outdoor sowing. Indoors, this is a busy month for starting cool-season crops and hardy flowers under lights or in a greenhouse so they are ready to transplant as soon as the weather warms.

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: bunching onion, eggplant, tomato, pepper, zinnia, basil, Swiss chard, cosmos

Transplants to move outdoors (weather permitting - harden first): Onion, parsley, broccoli, cabbage, kohlrabi, arugula, pansy, viola

Crops that can be directly sown outdoors in March (assume intermittent frosts; a low tunnel or row cover makes most of these reliable): pak choi, cabbage, kale, mustard, fava bean, pea, turnip, parsnip, sweet pea

Cover crops: winter rye, fava bean, hairy vetch, red or white clover, and cover crop mixes.

Tip: This zone group covers a lot of territory. Nothing takes the place of talking with experienced gardeners in your area and, of course, watching the weather closely.

Use your USDA zone as a guide. Microclimates matter—coastal/urban spots run warmer; high elevation runs colder. 7b pockets can follow “Mild” recommendations with protection.