When to Plant Garlic in Solano County, CA
Garlic is a pungent allium planted in fall and harvested the following summer. Hardneck varieties produce edible flower stalks (scapes) and are more cold-hardy.
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 95°F, so Garlic 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 Garlic's growing requirements.
Soil pH
Your soil pH (6.8–7.3) is within Garlic's preferred range (6.0–7.5).
Soil Texture
The loam soil in Solano County is excellent for Garlic — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Garlic.
Organic Matter
Organic matter is moderate (2.6%). Annual compost additions will help Garlic.
How to Plant Garlic
Fall planting: Sow 6 weeks before your first frost date for a fall harvest.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Garlic
Garlic needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Garlic Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 8.9" | 0" | ❄️ Dormant |
| Feb | 2.2" | 8.4" | 0" | ✅ Rainfall sufficient |
| Mar | 2.2" | 6.6" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 2.7" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 1" | 1.2" | 🚿 Regular watering |
| Jun | 2.2" | 0.2" | 2" | 🚿 Regular watering |
| Jul | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Aug | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Sep | 2.2" | 0.4" | 1.8" | 🚿 Regular watering |
| Oct | 2.2" | 1.9" | 0.3" | 💧 Light watering |
| Nov | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Dec | 2.2" | 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.
Garlic 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.
Garlic Planting Timeline — Solano County, CA
Garlic Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Fall Sowing | October 22 | Oct 22 – Nov 5 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | — |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | Fall Sowing |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Only during dry spells
📅 Days to Maturity
90–240 days
🧪 Soil pH
Needs 6–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 9a
📆 Growing Season
297 days in Solano County
Growing Tips for Garlic in Solano County
Direct sow Garlic outdoors after February 09 in Solano County when soil has warmed and frost danger has passed.
Common pests for Garlic in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.
General growing tips
Plant individual cloves pointed end up in fall, 6 weeks before ground freezes. Mulch heavily with straw. Harvest when lower leaves begin to brown but 5-6 green leaves remain.
Companion Planting
Good Companions
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Check more plant combinations with our Companion Planting Checker →
Garlic in Other Locations
Frequently Asked Questions
When should I plant Garlic in Solano County, CA?
Solano County is in Zone 9a with an average last frost of February 9. Plan your Garlic 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 9a. The average last spring frost is February 9 and first fall frost is December 3.
Plan Your Garden with Confidence
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