Plan your lettuce planting around local frost risk and soil temperature, then work backward from the harvest week your buyers need. The calendar below is a starting point, not a field-level weather forecast.
Grand Forks & Minot ND, northern MN border counties. Average last spring frost May 25, first fall frost September 10 — a 108-day frost-free season.
Windows are calculated from your zone's average frost dates. Adjust ±1 week for microclimates, elevation, and your own frost records.
Successive plantings every 10–14 days for continuous harvest. Bolts fast above 75°F — use heat-tolerant varieties past May.
Plant near: carrots, radish, strawberries
BAU Farm Intelligence turns these windows into per-field tasks — indoor seed-start reminders, transplant dates, harvest projections — using your farm's actual frost history.