Rosemary illustration 🌿

🌿 Growing Rosemary in Zone 5b

Zone 5b has cold winters and a moderate growing season. Timing is key for Rosemary in this zone. Last frost: Apr 28. First frost: Oct 8.

Planting Calendar

Indoor
Outdoor
Harvest
Feb 17Oct 8

Season: Apr 28 – Oct 8 (163 days)

Zone5b
Last FrostApr 28
First FrostOct 8
Season Length163 days
Days to Harvest90
SunFull Sun
Frost ToleranceLight
Spacing1/sqft (12" apart)

When to Plant Rosemary in Zone 5b

Start Seeds Indoors: Feb 17

Start Rosemary seeds indoors around Feb 17 (10 weeks before last frost). Optimal germination temperature: 70°F. Germinates in 14–28 days.

Transplant Outdoors: May 5

Transplant Rosemary seedlings outdoors after May 5. Wait until soil temperature reaches 55°F. Space plants at 1/sqft (12" apart). Harden off plants for a week before moving outside.

Harvest: Aug 3

First harvest approximately Aug 3 (~90 days from transplant). Continue harvesting until first frost (Oct 8). Rosemary can overwinter in mild climates for continued harvest.

Companion Planting

✅ Beans✅ Carrots✅ Cabbage

Frequently Asked Questions

When should I plant Rosemary in Zone 5b?

Start Rosemary seeds indoors around Feb 17. Transplant outdoors after May 5. Expect first harvest around Aug 3.

What is the last frost date for Zone 5b?

The average last spring frost date for Zone 5b is Apr 28. The first fall frost averages Oct 8, giving a 163-day growing season.

Can I grow Rosemary in Zone 5b?

Yes. Rosemary needs 90 days to harvest. Zone 5b has a 163-day growing season, which is sufficient.

What is the best month to plant Rosemary in Zone 5b?

The best time to start Rosemary in Zone 5b is Feb. Begin seeds indoors around Feb 17, then transplant outdoors after the last frost date of Apr 28.

What companion plants grow well with Rosemary?

Good companion plants for Rosemary include Beans, Carrots, Cabbage.

How long does Rosemary take to harvest?

Rosemary takes approximately 90 days from planting to harvest. In Zone 5b, expect your first harvest around Aug 3.

Plan Your Rosemary Garden

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

Start Free Rosemary Growing Guide