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When to Plant Rosemary in Coos County, OR

Rosemary

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.

Coos County, Oregon is in USDA Zone 9a. The average last spring frost is March 22 and the first fall frost is November 19, giving you a growing season of approximately 242 days.

At an elevation of 96 feet, Coos County receives approximately 38.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Rosemary during the growing season.

Coos County, OR (Zone 9a) Long season
242 days
Last Spring Frost March 22
242 growing days
First Fall Frost November 19

Coos County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Rosemary Planting Timeline — Coos County, OR

Rosemary Planting Calendar

Activity When Date Range
Transplant Outdoors March 29 Mar 29 – Apr 12
Harvest June 21 Jun 21 – Nov 8

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

80–180 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 9a

📆 Growing Season

242 days in Coos County

Growing Tips for Coos 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Rosemary in Coos County, OR?

Coos County is in Zone 9a with an average last frost of March 22. Plan your Rosemary planting based on this frost date — see the calendar above for exact timing.

What planting zone is Coos County, OR?

Coos County, Oregon is in USDA Hardiness Zone 9a. The average last spring frost is March 22 and first fall frost is November 19.

🌱

Your Coos County Garden Planner — Free

A 22-page printable planner built for Coos County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.