When to Plant Tarragon in Santa Clara County, CA
Top priorities for Santa Clara County, California gardeners in May
Your Santa Clara County, California garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
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Harvest tarragon as they ripen
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
To set up a strong June, finish these tasks
- 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.
Santa Clara County, California is in USDA Zone 9b. The average last spring frost is February 19 and the first fall frost is December 3, giving you a growing season of approximately 287 days.
At an elevation of 455 feet, Santa Clara County receives approximately 15.5 inches of rainfall annually with predominantly loam soil. Summer highs average 92°F, providing good warmth for Tarragon during the growing season. With low rainfall, drip irrigation is essential for growing Tarragon successfully. Mulch heavily to conserve soil moisture.
Santa Clara County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.8
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 Santa Clara County
How your county's soil matches Tarragon's growing requirements.
Soil pH
Your soil pH (6.7–7.8) overlaps with Tarragon's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Santa Clara County is excellent for Tarragon — good drainage, moisture retention, and nutrient holding capacity.
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 | — | 3.2" | 0" | ❄️ Dormant |
| Feb | 1.7" | 3.6" | 0" | ✅ Rainfall sufficient |
| Mar | 1.7" | 2.6" | 0" | ✅ Rainfall sufficient |
| Apr | 1.7" | 1.1" | 0.6" | 💧 Light watering |
| May | 1.7" | 0.3" | 1.4" | 🚿 Regular watering |
| Jun | 1.7" | 0.1" | 1.6" | 🚿 Regular watering |
| Jul | 1.7" | 0" | 1.7" | 🚿 Regular watering |
| Aug | 1.7" | 0" | 1.7" | 🚿 Regular watering |
| Sep | 1.7" | 0.1" | 1.6" | 🚿 Regular watering |
| Oct | 1.7" | 0.6" | 1.1" | 🚿 Regular watering |
| Nov | 1.7" | 1.4" | 0.3" | 💧 Light watering |
| Dec | 1.7" | 2.6" | 0" | ✅ Rainfall sufficient |
Water needs are for active growing months only (Feb–Dec in Santa Clara 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 — Santa Clara County, CA
Tarragon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | February 26 | Feb 26 – Mar 12 |
| Harvest | April 30 | Apr 30 – Jul 9 |
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 | Harvest |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.4"/week · Only during dry spells
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 9b
📆 Growing Season
287 days in Santa Clara County
Growing Tips for Tarragon in Santa Clara County
Direct sow Tarragon outdoors after February 19 in Santa Clara 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 Santa Clara County, CA?
Santa Clara County is in Zone 9b with an average last frost of February 19. Plan your Tarragon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Santa Clara County, CA?
Santa Clara County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 19 and first fall frost is December 3.
Your Santa Clara County Garden Planner — Free
A 24-page printable planner built for Santa Clara 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.