March is an early-spring planting month, but it can still bring hard freezes in northern gardens. Base every choice on your own soil temperature, frost dates, and USDA zone.

Start indoors in March

Start tomatoes about 6 to 8 weeks before their safe outdoor transplanting date, and start peppers and eggplants about 8 to 10 weeks before that date. Continue starting broccoli, cabbage, kale, and lettuce if they need a spring transplant window.

Plant outdoors: cool & northern regions (zones 3–6)

In zones 3 to 6, sow peas, spinach, lettuce, arugula, radishes, turnips, and other hardy crops once soil is workable, not muddy. Set out hardened-off brassica and onion seedlings when local conditions permit, and protect them from severe cold.

Plant outdoors: warm & southern regions (zones 7–10)

In zones 7 to 10, plant warm-season crops only after local frost risk has passed and soil has warmed, including beans, cucumbers, squash, and tomatoes in the warmest locations. Continue planting cool-season crops in areas that have not yet become hot.

Garden tasks for March

Work in compost only as needed and avoid deep tilling wet ground. Install supports for peas and plan trellises, irrigation, and frost protection before fast spring growth begins.

Regional guidance for US home gardens; always adjust to your own last and first frost dates. Page updated Aug 4, 2026.