What to Plant in March — Zone 5

March ends about 3 weeks before zone 5's average last frost (Apr 22) — prime seed-starting territory.

Start seeds indoors — Counted back from the last frost so transplants are ready on time.

🥬 Lettuce	Mar 11 – Mar 25	45–60 days to maturity
🥬 Kale	Mar 11 – Mar 25	55–65 days to maturity
🌈 Swiss Chard	Mar 18 – Apr 1	50–60 days to maturity
🍃 Collard Greens	Mar 11 – Mar 25	60–75 days to maturity
🥬 Cabbage	Feb 25 – Mar 11	65–85 days to maturity
🥦 Broccoli	Mar 4 – Mar 18	60–75 days to maturity
🥦 Cauliflower	Mar 4 – Mar 18	60–80 days to maturity
🥬 Brussels Sprouts	Mar 11 – Mar 25	90–110 days to maturity
🍅 Tomatoes	Feb 25 – Mar 11	60–85 days to maturity
🍏 Tomatillos	Feb 25 – Mar 11	70–80 days to maturity
🥒 Cucumbers	Mar 25 – Apr 1	50–70 days to maturity
🥒 Zucchini	Mar 25 – Apr 1	45–60 days to maturity
🎃 Winter Squash	Mar 25 – Apr 1	85–110 days to maturity
🎃 Pumpkins	Mar 25 – Apr 1	90–110 days to maturity
🍉 Watermelon	Mar 25 – Apr 1	75–95 days to maturity
🍈 Cantaloupe	Mar 25 – Apr 1	75–90 days to maturity
🌶️ Okra	Mar 25 – Apr 1	55–65 days to maturity
🌿 Basil	Mar 11 – Mar 25	30–60 days to maturity
🌱 Chives	Feb 25 – Mar 11	75–85 days to maturity
🌿 Oregano	Feb 25 – Mar 11	80–90 days to maturity
🌸 Zinnias	Mar 25 – Apr 1	60–70 days to maturity
🏵️ Marigolds	Mar 11 – Mar 25	50–60 days to maturity

Transplant outdoors — Set out sturdy transplants during these windows.

🥬 Lettuce	Mar 25 – Apr 8	45–60 days to maturity
🥬 Kale	Mar 25 – Apr 8	55–65 days to maturity
🍃 Collard Greens	Mar 25 – Apr 8	60–75 days to maturity
🥬 Cabbage	Mar 25 – Apr 8	65–85 days to maturity
🧅 Onions	Mar 11 – Mar 25	90–110 days to maturity
🧅 Leeks	Mar 25 – Apr 8	100–120 days to maturity

Direct sow — Seeds straight into garden soil.

🫛 Peas	Mar 11 – Mar 25	55–70 days to maturity
🥬 Lettuce	Mar 25 – Apr 22	45–60 days to maturity
🍃 Spinach	Mar 11 – Mar 25	40–50 days to maturity
🥬 Kale	Mar 25 – Apr 8	55–65 days to maturity
🌿 Arugula	Mar 18 – Apr 1	30–40 days to maturity
🥬 Kohlrabi	Mar 25 – Apr 8	45–60 days to maturity
🫒 Beets	Mar 25 – Apr 8	50–65 days to maturity
🌶️ Radishes	Mar 18 – Apr 1	22–30 days to maturity
🥔 Turnips	Mar 25 – Apr 8	40–55 days to maturity
🧅 Onions	Mar 25 – Apr 8	90–110 days to maturity
🧅 Scallions	Mar 25 – Apr 8	60–70 days to maturity
🥔 Potatoes	Mar 25 – Apr 8	70–100 days to maturity
🌿 Mustard Greens	Mar 25 – Apr 8	35–45 days to maturity

Windows use zone 5's typical frost dates (Apr 22 / Oct 12). For your own city's dates, run the frost lookup — the planting calendar then localizes everything automatically.

Frequently asked questions

What can I plant outside in March in zone 5?

16 crops can go in the ground: lettuce, kale, collard greens, cabbage, onions, leeks, peas, spinach, and 8 more. Exact windows are in the tables above — early and late in the month can differ by a full frost date.

What seeds should I start indoors in March in zone 5?

Lettuce, kale, swiss chard, collard greens, cabbage, broccoli, cauliflower, brussels sprouts, and 14 more — each is counted back from zone 5's average last frost around Apr 22, so transplants are ready exactly when the garden is.

Is March the right time for tomatoes in zone 5?

For seed-starting, yes: sow indoors Feb 25 – Mar 11. Transplanting waits until after the Apr 22 average last frost.