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When to Plant Rosemary in Barnstable County, MA

Rosemary is an aromatic evergreen shrub with needle-like leaves and a piney, citrus flavor. It is a Mediterranean herb that thrives in warm, dry conditions.

Barnstable County, Massachusetts is in USDA Zone 7a. The average last spring frost is April 18 and the first fall frost is October 24, giving you a growing season of approximately 189 days.

At an elevation of 518 feet, Barnstable County receives approximately 45.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91ยฐF, providing good warmth for Rosemary during the growing season.

Barnstable County, MA (Zone 7a) Moderate season
189 days
Last Spring Frost April 18
189 growing days
First Fall Frost October 24

Barnstable County Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 17 🍅 Harvest: Jul 10 – Nov 27
Recommended (50%) ✗ May not fit
Transplant: Apr 25 🍅 Harvest: Jul 18 – Dec 5
Safe Start (90%) ✗ May not fit
Transplant: May 18 🍅 Harvest: Aug 10 – Dec 28

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Rosemary needs ~2,372 GDD — county provides 3,449 GDD Excellent fit

Rosemary Planting Timeline โ€” Barnstable County, MA

Rosemary Planting Calendar

Activity When Date Range
Transplant Outdoors April 25 Apr 25 โ€“ May 9
Harvest July 18 Jul 18 โ€“ Dec 5

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Transplant Outdoors
May Transplant Outdoors
June โ€”
July Harvest
August Harvest
September Harvest
October Harvest
November Harvest
December Harvest

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

80โ€“180 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 7a

Growing Season

189 days

Growing Tips for Barnstable County

Grow in well-drained soil and avoid overwatering. In cold climates, grow in containers and bring indoors for winter. Propagate from stem cuttings for faster results than seed.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Rosemary in Barnstable County, MA?

Barnstable County is in Zone 7a with an average last frost of April 18. Plan your Rosemary planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Barnstable County, MA?

Barnstable County, Massachusetts is in USDA Hardiness Zone 7a. The average last spring frost is April 18 and first fall frost is October 24.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Barnstable County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.

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Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Barnstable County, MA. Local conditions may vary. Last updated: April 2026.