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When to Plant Patty Pan Squash in Contra Costa County, CA

Contra Costa County, California Zone 9b May

May in the garden — Contra Costa County, California

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Contra Costa County, California.

Avg. last frost February 26
Avg. first frost November 29
Soil temp (4") 78°F
Watering Critical
Pest pressure High
Daylight 14 hrs
  1. Collect patty pan squash at their peak

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

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Patty pan squash is a summer squash with a distinctive flying-saucer shape and scalloped edges. It comes in white, yellow, and green varieties with a mild, nutty flavor.

Contra Costa County, California is in USDA Zone 9b. The average last spring frost is February 26 and the first fall frost is November 29, giving you a growing season of approximately 276 days.

At an elevation of 88 feet, Contra Costa County receives approximately 19 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Patty Pan Squash during the growing season. With low rainfall, drip irrigation is essential for growing Patty Pan Squash successfully. Mulch heavily to conserve soil moisture.

Contra Costa County, CA (Zone 9b) Year-round
276 days
Last Spring Frost February 26
276 growing days
First Fall Frost November 29
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Contra Costa County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (207 days to spare)
Start indoors: Jan 8 Transplant: Feb 12 🍅 Harvest: Apr 2 – Apr 30
Recommended (50%) ✓ Fits season (192 days to spare)
Start indoors: Jan 29 Transplant: Mar 5 🍅 Harvest: Apr 23 – May 21
Safe Start (90%) ✓ Fits season (177 days to spare)
Start indoors: Mar 5 Transplant: Apr 9 🍅 Harvest: May 28 – Jun 25

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 Contra Costa County

How your county's soil matches Patty Pan Squash's growing requirements.

Soil pH

Your soil pH (6.7–7.8) overlaps with Patty Pan Squash's range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Contra Costa County is excellent for Patty Pan Squash — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.0%). Annual compost additions will help Patty Pan Squash.

How to Plant Patty Pan Squash

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

Succession Planting Patty Pan Squash

7
successive plantings in your 276-day season

Sow every 5.1 weeks. Last sowing by Sep 30 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.3″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 2,106 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Patty Pan Squash

Patty Pan Squash needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Patty Pan Squash Needs Rainfall You Supplement Action
Jan 4.1" 0" ❄️ Dormant
Feb 4.3" 4.5" 0" ✅ Rainfall sufficient
Mar 4.3" 3" 1.3" 💧 Light watering
Apr 4.3" 1.5" 2.8" 🚿 Regular watering
May 4.3" 0.6" 3.7" 🚿 Regular watering
Jun 4.3" 0.1" 4.2" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.2" 4.1" 🚿 Regular watering
Oct 4.3" 0.7" 3.6" 🚿 Regular watering
Nov 4.3" 1.6" 2.7" 🚿 Regular watering
Dec 2.7" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Contra Costa County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Patty Pan 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.

Patty Pan Squash needs ~1,037 GDD — county provides 5,470 GDD Excellent fit

Patty Pan Squash Planting Timeline — Contra Costa County, CA

Patty Pan Squash Planting Calendar

Activity When Date Range
Start Indoors January 29 Jan 29 – Feb 12
Transplant Outdoors March 5 Mar 5 – Mar 19
Direct Sow February 26 Feb 26 – Mar 19
Harvest April 23 Apr 23 – May 21

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

45–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

276 days in Contra Costa County

Growing Tips for Patty Pan Squash in Contra Costa County

Direct sow Patty Pan Squash outdoors after February 26 in Contra Costa County when soil has warmed and frost danger has passed.

Your generous 277.0-day season in Contra Costa County allows multiple plantings of Patty Pan Squash. Sow every 22.0 days for continuous harvest.

Common pests for Patty Pan Squash in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

Contra Costa County receives only 19" of rain annually. Patty Pan Squash needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after last frost. Harvest when 2-4 inches across for best texture and flavor. Larger fruits become seedy and tough. Very prolific producers in warm weather.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Patty Pan Squash in Contra Costa County, CA?

Contra Costa County is in Zone 9b with an average last frost of February 26. Plan your Patty Pan Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Contra Costa County, CA?

Contra Costa County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 26 and first fall frost is November 29.

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Your Contra Costa County Garden Planner — Free

A 24-page printable planner built for Contra Costa 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Contra Costa 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.