Nasturtium illustration 🌺

🌺 Growing Nasturtium in Zone 4b

Zone 4b has cold winters and a moderate growing season. Timing is key for Nasturtium in this zone. Last frost: May 1. First frost: Oct 5.

Planting Calendar

Indoor
Outdoor
Harvest
Apr 3Oct 5

Season: May 1 – Oct 5 (157 days)

Zone4b
Last FrostMay 1
First FrostOct 5
Season Length157 days
Days to Harvest45
SunFull Sun
Frost ToleranceNone
Spacing4/sqft (6" apart)

When to Plant Nasturtium in Zone 4b

Start Seeds Indoors: Apr 3

Start Nasturtium seeds indoors around Apr 3 (4 weeks before last frost). Optimal germination temperature: 70°F. Germinates in 7–14 days.

Transplant Outdoors: May 8

Transplant Nasturtium seedlings outdoors after May 8. Wait until soil temperature reaches 55°F. Space plants at 4/sqft (6" apart). Harden off plants for a week before moving outside.

Harvest: Jun 17

First harvest approximately Jun 17 (~40 days from transplant). Continue harvesting until first frost (Oct 5).

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