When to plant eggplant in USDA Zone 5b

Plan your eggplant 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.

Chicago, Des Moines suburbs, central IL, upstate NY. Average last spring frost May 1, first fall frost October 6 — a 158-day frost-free season.

Zone fit: good
Eggplant is frost-tender, so timing the outdoor transplant to the last frost matters more here than in warmer zones. Row cover buys 2 weeks of head start.

Key dates

Start seeds indoors
February 27 – March 13
Transplant outdoors
May 15 – June 5
Expected first harvest
August 10 – September 7
Fall planting window
June 23 – July 14
Fall harvest window
September 18 – October 16

Windows are calculated from your zone's average frost dates. Adjust ±1 week for microclimates, elevation, and your own frost records.

Spacing and soil

Plant spacing
24″
Row spacing
36″
Seed depth
0.25″
Soil temperature
75–90°F
Frost tolerance
tender
Days to harvest
80 days

Grower notes for Zone 5b

Flea beetle pressure is highest in early season; use row cover for the first 3 weeks after transplant.

Plant near: beans, peppers, marigolds

Keep away from: fennel

Other nightshades for Zone 5b

Same crop, other zones

Track your own plantings

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.