Nasturtium illustration 🌺

🌺 Growing Nasturtium in Zone 3b

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

Planting Calendar

Indoor
Outdoor
Harvest
Apr 17Sep 22

Season: May 15 – Sep 22 (130 days)

Zone3b
Last FrostMay 15
First FrostSep 22
Season Length130 days
Days to Harvest45
SunFull Sun
Frost ToleranceNone
Spacing4/sqft (6" apart)

When to Plant Nasturtium in Zone 3b

Start Seeds Indoors: Apr 17

Start Nasturtium seeds indoors around Apr 17 (4 weeks before last frost). Optimal germination temperature: 70°F. Germinates in 7–14 days.

Transplant Outdoors: May 22

Transplant Nasturtium seedlings outdoors after May 22. Wait until soil temperature reaches 55°F. Space plants at 4/sqft (6" apart). Harden off plants for a week before moving outside.

Harvest: Jul 1

First harvest approximately Jul 1 (~40 days from transplant). Continue harvesting until first frost (Sep 22).

Companion Planting

✅ Cucumbers✅ Squash✅ Pumpkins✅ Radishes✅ Cabbage

Plan Your Nasturtium Garden

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

Start Free Nasturtium Growing Guide