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When to Plant Thyme in Solano County, CA

Thyme is a low-growing perennial herb with tiny, aromatic leaves and a warm, earthy flavor. It is one of the most versatile culinary and medicinal herbs.

Solano County, California is in USDA Zone 9a. The average last spring frost is February 9 and the first fall frost is December 3, giving you a growing season of approximately 297 days.

At an elevation of 376 feet, Solano County receives approximately 40.4 inches of rainfall annually with predominantly loam soil. Summer highs average 95Β°F, so Thyme may need afternoon shade and extra watering during peak heat.

Solano County, CA (Zone 9a) Year-round
297 days
Last Spring Frost February 9
297 growing days
First Fall Frost December 3

Solano County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.3

Drainage

Well Drained

Monthly Watering Guide for Thyme

Thyme needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Thyme Needs Rainfall You Supplement Action
Jan β€” 8.9" 0" ❄️ Dormant
Feb 4.3" 8.4" 0" βœ… Rainfall sufficient
Mar 4.3" 6.6" 0" βœ… Rainfall sufficient
Apr 4.3" 2.7" 1.6" πŸ’§ Light watering
May 4.3" 1" 3.3" 🚿 Regular watering
Jun 4.3" 0.2" 4.1" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.4" 3.9" 🚿 Regular watering
Oct 4.3" 1.9" 2.4" 🚿 Regular watering
Nov 4.3" 3.3" 1" πŸ’§ Light watering
Dec 4.3" 7.1" 0" βœ… Rainfall sufficient

Water needs are for active growing months only (Feb–Dec in Solano County). Supplement amounts are based on average rainfall β€” actual needs vary with temperature, soil, and mulching.

Thyme Planting Timeline β€” Solano County, CA

Thyme Planting Calendar

Activity When Date Range
Transplant Outdoors February 16 Feb 16 – Mar 2
Harvest April 27 Apr 27 – Jun 29

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

Month-by-Month Timeline

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

Growing Conditions

β˜€οΈ Sun

Full Sun (6-8+ hours)

πŸ’§ Water

Low β€” drought tolerant

πŸ“… Days to Maturity

70–90 days

πŸ§ͺ Soil pH

Needs 6–8 Β· Your soil: N/A

πŸ—ΊοΈ USDA Zone

Zone 9a

πŸ“† Growing Season

297 days in Solano County

Growing Tips for Solano County

Start from seed, cuttings, or divisions. Plant in well-drained, lean soil. Prune lightly after flowering. Replace plants every 3-4 years when they become woody.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Thyme in Solano County, CA?

Solano County is in Zone 9a with an average last frost of February 9. Plan your Thyme planting based on this frost date β€” see the calendar above for exact timing.

What planting zone is Solano County, CA?

Solano County, California is in USDA Hardiness Zone 9a. The average last spring frost is February 9 and first fall frost is December 3.

🌱

Plan Your Garden with Confidence

Get our free Garden Planner β€” designed to help Solano County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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 Solano County, CA. Local conditions may vary. Last updated: April 2026.