Kale illustration 🥬

🥬 Growing Kale in Zone 3b

Zone 3b has harsh winters and a short growing season. Start Kale early indoors to maximize your harvest window. Last frost: May 15. First frost: Sep 22.

Planting Calendar

Indoor
Outdoor
Harvest
Apr 3Sep 22

Season: May 15 – Sep 22 (130 days)

Zone3b
Last FrostMay 15
First FrostSep 22
Season Length130 days
Days to Harvest60
SunPart Sun / Part Shade
Frost ToleranceHeavy
Spacing1/sqft (12" apart)

When to Plant Kale in Zone 3b

Start Seeds Indoors: Apr 3

Start Kale seeds indoors around Apr 3 (6 weeks before last frost). Optimal germination temperature: 65°F. Germinates in 5–10 days.

Transplant Outdoors: Apr 17

Transplant Kale seedlings outdoors after Apr 17. Wait until soil temperature reaches 40°F. Space plants at 1/sqft (12" apart). Harden off plants for a week before moving outside.

Harvest: Jun 1

First harvest approximately Jun 1 (~45 days from transplant). Continue harvesting until first frost (Sep 22). Kale can overwinter in mild climates for continued harvest.

Fall Planting: Jul 28

For a fall harvest, plant Kale around Jul 28 (8 weeks before first frost).

Companion Planting

✅ Sage✅ Dill✅ Onions✅ Beets✅ Potatoes
❌ Strawberries

Plan Your Kale Garden

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

Start Free Kale Growing Guide