What to Plant in March — Zone 4

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

🥬 Lettuce	Mar 24 – Apr 7	45–60 days to maturity
🥬 Kale	Mar 24 – Apr 7	55–65 days to maturity
🌈 Swiss Chard	Mar 31 – Apr 14	50–60 days to maturity
🍃 Collard Greens	Mar 24 – Apr 7	60–75 days to maturity
🥬 Cabbage	Mar 10 – Mar 24	65–85 days to maturity
🥦 Broccoli	Mar 17 – Mar 31	60–75 days to maturity
🥦 Cauliflower	Mar 17 – Mar 31	60–80 days to maturity
🥬 Brussels Sprouts	Mar 24 – Apr 7	90–110 days to maturity
🧅 Onions	Feb 24 – Mar 10	90–110 days to maturity
🧅 Leeks	Feb 24 – Mar 10	100–120 days to maturity
🥬 Celery	Feb 24 – Mar 10	100–120 days to maturity
🍅 Tomatoes	Mar 10 – Mar 24	60–85 days to maturity
🫑 Peppers	Feb 24 – Mar 10	60–90 days to maturity
🍆 Eggplant	Feb 24 – Mar 10	65–80 days to maturity
🍏 Tomatillos	Mar 10 – Mar 24	70–80 days to maturity
🌿 Basil	Mar 24 – Apr 7	30–60 days to maturity
🌿 Parsley	Feb 24 – Mar 10	70–90 days to maturity
🌱 Chives	Mar 10 – Mar 24	75–85 days to maturity
🌿 Thyme	Feb 24 – Mar 10	90–120 days to maturity
🌿 Oregano	Mar 10 – Mar 24	80–90 days to maturity
🏵️ Marigolds	Mar 24 – Apr 7	50–60 days to maturity

Transplant outdoors — Set out sturdy transplants during these windows.

🧅 Onions

Mar 24 – Apr 7

90–110 days to maturity

Direct sow — Seeds straight into garden soil.

🫛 Peas	Mar 24 – Apr 7	55–70 days to maturity
🍃 Spinach	Mar 24 – Apr 7	40–50 days to maturity
🌿 Arugula	Mar 31 – Apr 14	30–40 days to maturity
🌶️ Radishes	Mar 31 – Apr 14	22–30 days to maturity

Windows use zone 4's typical frost dates (May 5 / Oct 1). For your own city's dates, run the frost lookup — the planting calendar then localizes everything automatically.