Blog

When to Plant Acorn Squash in Tuolumne County, CA

Tuolumne County, California Zone 9b May

May to-do list for Tuolumne County, California

May is a pivotal month for Tuolumne County, California gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 25
Avg. first frost October 27
Soil temp (4") 62°F
Watering Critical
Pest pressure Moderate
Daylight 14.1 hrs
  1. Move acorn squash from tray to bed

    Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.

  2. Begin indoor sowing: acorn squash

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

Instant PDF download. No spam, unsubscribe any time.

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.

Tuolumne County, California is in USDA Zone 9b. The average last spring frost is April 25 and the first fall frost is October 27, giving you a growing season of approximately 185 days.

At an elevation of 2,990 feet, Tuolumne County receives approximately 37.7 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Acorn Squash during the growing season.

Tuolumne County, CA (Zone 9b) Moderate season
185 days
Last Spring Frost April 25
185 growing days
First Fall Frost October 27

Tuolumne County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (30 days to spare)
Start indoors: Mar 17 Transplant: Apr 21 🍅 Harvest: Jul 14 – Aug 18
Recommended (50%) ✓ Fits season (59 days to spare)
Start indoors: Mar 28 Transplant: May 2 🍅 Harvest: Jul 25 – Aug 29
Safe Start (90%) ✓ Fits season (24 days to spare)
Start indoors: May 23 Transplant: Jun 27 🍅 Harvest: Sep 19 – Oct 24

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 Tuolumne County

How your county's soil matches Acorn Squash's growing requirements.

Soil pH

Your soil pH (6.6–7.5) 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 Tuolumne County is excellent for Acorn Squash — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Acorn Squash.

How to Plant Acorn Squash

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Acorn Squash

2
successive plantings in your 185-day season

Sow every 9.1 weeks. Last sowing by Jul 19 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.9″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 482 gal / 100 sq ft
Drought risk

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 7.8" 0" ❄️ Dormant
Feb 8.2" 0" ❄️ Dormant
Mar 6.7" 0" ❄️ Dormant
Apr 4.8" 2.8" 2" 💧 Light watering
May 4.8" 1.1" 3.7" 🚿 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" 1.5" 3.3" 🚿 Regular watering
Nov 3" 0" ❄️ Dormant
Dec 6.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Tuolumne 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 needs ~1,440 GDD — county provides 2,960 GDD Excellent fit

Acorn Squash Planting Timeline — Tuolumne County, CA

Acorn Squash Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 – Apr 11
Transplant Outdoors May 2 May 2 – May 16
Direct Sow April 25 Apr 25 – May 16
Harvest July 25 Jul 25 – Aug 29

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June
July Harvest
August Harvest
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · Only during dry spells

📅 Days to Maturity

80–100 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

185 days in Tuolumne County

Growing Tips for Acorn Squash in Tuolumne County

Direct sow Acorn Squash outdoors after April 25 in Tuolumne 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

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Acorn Squash in Tuolumne County, CA?

Tuolumne County is in Zone 9b with an average last frost of April 25. Plan your Acorn Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Tuolumne County, CA?

Tuolumne County, California is in USDA Hardiness Zone 9b. The average last spring frost is April 25 and first fall frost is October 27.

🌱

Your Tuolumne County Garden Planner — Free

A 24-page printable planner built for Tuolumne 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Tuolumne County, CA. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.