When should I plant Soybean in Zone 3a?

Direct sow Soybean outdoors around May 29. Harvest around Sep 16.

What is the last frost date for Zone 3a?

The average last spring frost date for Zone 3a is May 22. The first fall frost averages Sep 12, giving a 113-day growing season.

Can I grow Soybean in Zone 3a?

Yes. Soybean needs 110 days to harvest. Zone 3a has a 113-day growing season, which is sufficient.

Growing Soybean in Zone 3a

Zone 3a has harsh winters and a short growing season. Start Soybean early indoors to maximize your harvest window. Last frost: May 22. First frost: Sep 12.

Planting Calendar

Outdoor

Harvest

May 29Sep 12

Season: May 22 – Sep 12 (113 days)

Zone3a

Last FrostMay 22

First FrostSep 12

Season Length113 days

Days to Harvest110

SunFull Sun

Frost ToleranceNone

Spacing4/sqft (6" apart)

When to Plant Soybean in Zone 3a

Sow Seeds Outdoors: May 29

Direct sow Soybean seeds outdoors around May 29. Soil temperature should be at least 60°F. Space at 4/sqft (6" apart).

Harvest: Sep 16

First harvest approximately Sep 16 (~110 days from planting). Continue harvesting until first frost (Sep 12).

Companion Planting

✅ Corn ✅ Squash ✅ Sesame

❌ Onion❌ Garlic

Soybean in Other Zones

1a 1b 2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a 10b 11a 11b 12a 12b 13a 13b

Plan Your Soybean Garden

Track Soybean from seed to harvest with personalized frost dates, watering recommendations, and companion planting visualization.

Start Free Soybean Growing Guide