March garden tasks: Northeast and Long Island
March in the Northeast is the month that tests patience. At my Long Island house (zone 7a), the average last frost date is April 7 -- which means March is still frost territory, but the ground thaws in the first two weeks and the calendar pressure to start something is intense. The correct response.
March in the Northeast is the month that tests patience. At my Long Island house (zone 7a), the average last frost date is April 7 — which means March is still frost territory, but the ground thaws in the first two weeks and the calendar pressure to start something is intense. The correct response is to do specific things on schedule and wait on everything else.
Per Cornell Cooperative Extension, the average last frost dates for major Northeast cities: New York City April 1—7, Boston April 15—20, Hartford April 20, Albany May 1, Portland ME May 7. Check your county-specific last frost date before making any planting decisions.
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Indoor seed starting
March is prime seed-starting time for warm-season crops in zones 6—7. Per Cornell Cooperative Extension, count backward from last frost date:
- Tomatoes: start 6—8 weeks before last frost → March 1—15 for zone 7 (last frost April 7)
- Peppers: start 8—10 weeks before last frost → February 15—March 1 for zone 7 (start in February if you haven't already)
- Eggplant: start 8—10 weeks before last frost
- Celery: start 10—12 weeks before transplant
- Leeks: start 10—12 weeks before transplant
For zone 5 (last frost around May 10): tomatoes start mid-March; peppers start early March.
Per Penn State Extension, the minimum setup for reliable indoor seed starting:
- Light: fluorescent or LED grow lights positioned 2—4 inches above seedlings for 14—16 hours per day; natural window light alone is insufficient for stocky transplants in most northeastern homes
- Soil: use sterile seed-starting mix, not garden soil
- Heat: germinate at 70—80°F; use a seedling heat mat for peppers and tomatoes
- After germination: move to 65°F day/55°F night to prevent leggy growth