Borage illustration

Growing Borage in Zone 4b

Zone 4b has cold winters and a moderate growing season. Timing is key for Borage 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 Harvest55
SunFull Sun
Frost ToleranceLight
Spacing18/sqft

When to Plant Borage in Zone 4b

Start Seeds Indoors: Apr 3

Start Borage seeds indoors around Apr 3 (4 weeks before last frost). Optimal germination temperature: 70°F. Germinates in 5–14 days.

Transplant Outdoors: May 1

Transplant Borage seedlings outdoors after May 1. Wait until soil temperature reaches 50°F. Space plants at 18/sqft. Harden off plants for a week before moving outside.

Harvest: Jun 25

First harvest approximately Jun 25 (~55 days from planting). Continue harvesting until first frost (Oct 5).

Companion Planting

✅ Strawberries✅ Tomatoes✅ Squash✅ Cucumbers

Frequently Asked Questions

When should I plant Borage in Zone 4b?

Start Borage seeds indoors around Apr 3. Transplant outdoors after May 1. Expect first harvest around Jun 25.

What is the last frost date for Zone 4b?

The average last spring frost date for Zone 4b is May 1. The first fall frost averages Oct 5, giving a 157-day growing season.

Can I grow Borage in Zone 4b?

Yes. Borage needs 55 days to harvest. Zone 4b has a 157-day growing season, which is sufficient.

What is the best month to plant Borage in Zone 4b?

The best time to start Borage in Zone 4b is Apr. Begin seeds indoors around Apr 3, then transplant outdoors after the last frost date of May 1.

What companion plants grow well with Borage?

Good companion plants for Borage include Strawberries, Tomatoes, Squash, Cucumbers.

How long does Borage take to harvest?

Borage takes approximately 55 days from planting to harvest. In Zone 4b, expect your first harvest around Jun 25.

Plan Your Borage Garden

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

Start Free Borage Growing Guide