When to Plant Acorn Squash in Solano County, CA
Your May gardening checklist
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.
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It's harvest week for acorn squash
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
June will be here before you know it — start on
- First harvests: acorn squash
Acorn squash is a small winter squash with dark green, ribbed skin and mildly sweet orange flesh. It is perfect for stuffing and roasting as individual servings.
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 Acorn Squash 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 Acorn Squash's growing requirements.
Soil pH
Your soil pH (6.8–7.3) is more alkaline than Acorn Squash prefers (5.5–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Solano County is excellent for Acorn Squash — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Acorn Squash.
Organic Matter
Organic matter is moderate (2.6%). Annual compost additions will help Acorn Squash.
How to Plant Acorn Squash
Succession Planting Acorn Squash
Sow every 9.1 weeks. Last sowing by Aug 25 to harvest before frost.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Acorn Squash
Acorn Squash needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.
| Month | Acorn Squash Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 8.9" | 0" | ❄️ Dormant |
| Feb | 4.8" | 8.4" | 0" | ✅ Rainfall sufficient |
| Mar | 4.8" | 6.6" | 0" | ✅ Rainfall sufficient |
| Apr | 4.8" | 2.7" | 2.1" | 💧 Light watering |
| May | 4.8" | 1" | 3.8" | 🚿 Regular watering |
| Jun | 4.8" | 0.2" | 4.6" | 🚿 Regular watering |
| Jul | 4.8" | 0" | 4.8" | 🚿 Regular watering |
| Aug | 4.8" | 0" | 4.8" | 🚿 Regular watering |
| Sep | 4.8" | 0.4" | 4.4" | 🚿 Regular watering |
| Oct | 4.8" | 1.9" | 2.9" | 🚿 Regular watering |
| Nov | 4.8" | 3.3" | 1.5" | 💧 Light watering |
| Dec | 4.8" | 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.
Acorn Squash 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.
Acorn Squash Planting Timeline — Solano County, CA
Acorn Squash Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 12 | Jan 12 – Jan 26 |
| Transplant Outdoors | February 16 | Feb 16 – Mar 2 |
| Direct Sow | February 9 | Feb 9 – Mar 2 |
| Harvest | May 11 | May 11 – Jun 15 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Transplant Outdoors Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | — |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1.1"/week · 2-3 times/week
📅 Days to Maturity
80–100 days
🧪 Soil pH
Needs 5.5–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 9b
📆 Growing Season
297 days in Solano County
Growing Tips for Acorn Squash in Solano County
Direct sow Acorn Squash outdoors after February 09 in Solano County when soil has warmed and frost danger has passed.
Common pests for Acorn Squash in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow after last frost. Harvest when the ground spot turns orange and the skin is hard. Acorn squash has a shorter storage life than butternut, lasting about 2 months.
Companion Planting
Good Companions
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Check more plant combinations with our Companion Planting Checker →
Acorn Squash in Other Locations
Frequently Asked Questions
When should I plant Acorn Squash in Solano County, CA?
Solano County is in Zone 9b with an average last frost of February 9. Plan your Acorn Squash 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.