When to Plant Tarragon in Solano County, CA
Solano County, California gardeners: here's your May plan
Here's what deserves your attention in Solano County, California this month. Everything below is tailored to Zone 9b and timed around your local frost dates.
-
Pick tarragon
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
Coming up in June — start thinking about
- First harvests: tarragon
French tarragon is a perennial herb with slender leaves and a distinctive anise-like flavor essential in French cooking. It does not produce viable seed and must be propagated vegetatively.
Solano County, California is in USDA Zone 9b. 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 95°F, so Tarragon may need afternoon shade and extra watering during peak heat.
Solano County Soil Profile
Soil Type
Loam
Soil pH
6.8-7.3
Drainage
Well Drained
Plant Planting Risk Windows
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.
Soil Compatibility in Solano County
How your county's soil matches Tarragon's growing requirements.
Soil pH
Your soil pH (6.8–7.3) is within Tarragon's preferred range (6.0–7.5).
Soil Texture
The loam soil in Solano County is excellent for Tarragon — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Tarragon.
Organic Matter
Organic matter is moderate (2.6%). Annual compost additions will help Tarragon.
How to Plant Tarragon
Succession Planting Tarragon
Sow every 6.9 weeks. Last sowing by Sep 04 to harvest before frost.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Tarragon
Tarragon needs approximately 0.4 inches of water per week (1.7" per month). Here's how your county's rainfall compares month by month.
| Month | Tarragon Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 8.9" | 0" | ❄️ Dormant |
| Feb | 1.7" | 8.4" | 0" | ✅ Rainfall sufficient |
| Mar | 1.7" | 6.6" | 0" | ✅ Rainfall sufficient |
| Apr | 1.7" | 2.7" | 0" | ✅ Rainfall sufficient |
| May | 1.7" | 1" | 0.7" | 💧 Light watering |
| Jun | 1.7" | 0.2" | 1.5" | 🚿 Regular watering |
| Jul | 1.7" | 0" | 1.7" | 🚿 Regular watering |
| Aug | 1.7" | 0" | 1.7" | 🚿 Regular watering |
| Sep | 1.7" | 0.4" | 1.3" | 🚿 Regular watering |
| Oct | 1.7" | 1.9" | 0" | ✅ Rainfall sufficient |
| Nov | 1.7" | 3.3" | 0" | ✅ Rainfall sufficient |
| Dec | 1.7" | 7.1" | 0" | ✅ Rainfall sufficient |
Water needs are for active growing months only (Feb–Dec in Solano County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Tarragon Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Tarragon Planting Timeline — Solano County, CA
Tarragon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | February 16 | Feb 16 – Mar 2 |
| Harvest | April 20 | Apr 20 – Jun 29 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Transplant Outdoors |
| March | Transplant Outdoors |
| April | Harvest |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.4"/week · Natural rainfall sufficient
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 9b
📆 Growing Season
297 days in Solano County
Growing Tips for Tarragon in Solano County
Direct sow Tarragon outdoors after February 09 in Solano County when soil has warmed and frost danger has passed.
Common pests for Tarragon in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
General growing tips
Purchase plants or divisions as French tarragon does not grow true from seed. Plant in well-drained soil. Divide every 3-4 years to maintain vigor. Harvest tips regularly for best flavor.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Tarragon in Other Locations
Frequently Asked Questions
When should I plant Tarragon in Solano County, CA?
Solano County is in Zone 9b with an average last frost of February 9. Plan your Tarragon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Solano County, CA?
Solano County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 9 and first fall frost is December 3.
Your Solano County Garden Planner — Free
A 24-page printable planner built for Solano County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.