Nasturtium illustration 🌺

🌺 Growing Nasturtium in Zone 4a

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

Planting Calendar

Indoor
Outdoor
Harvest
Apr 7Oct 1

Season: May 5 – Oct 1 (149 days)

Zone4a
Last FrostMay 5
First FrostOct 1
Season Length149 days
Days to Harvest45
SunFull Sun
Frost ToleranceNone
Spacing4/sqft (6" apart)

When to Plant Nasturtium in Zone 4a

Start Seeds Indoors: Apr 7

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

Transplant Outdoors: May 12

Transplant Nasturtium seedlings outdoors after May 12. 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 21

First harvest approximately Jun 21 (~40 days from transplant). Continue harvesting until first frost (Oct 1).

Companion Planting

✅ Cucumbers✅ Squash✅ Pumpkins✅ Radishes✅ Cabbage

Frequently Asked Questions

When should I plant Nasturtium in Zone 4a?

Start Nasturtium seeds indoors around Apr 7. Transplant outdoors after May 12. Expect first harvest around Jun 21.

What is the last frost date for Zone 4a?

The average last spring frost date for Zone 4a is May 5. The first fall frost averages Oct 1, giving a 149-day growing season.

Can I grow Nasturtium in Zone 4a?

Yes. Nasturtium needs 45 days to harvest. Zone 4a has a 149-day growing season, which is sufficient.

What is the best month to plant Nasturtium in Zone 4a?

The best time to start Nasturtium in Zone 4a is Apr. Begin seeds indoors around Apr 7, then transplant outdoors after the last frost date of May 5.

What companion plants grow well with Nasturtium?

Good companion plants for Nasturtium include Cucumbers, Squash, Pumpkins, Radishes, Cabbage.

How long does Nasturtium take to harvest?

Nasturtium takes approximately 45 days from planting to harvest. In Zone 4a, expect your first harvest around Jun 21.

Plan Your Nasturtium Garden

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

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