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When to Plant Patty Pan Squash in Riverside County, CA

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.

Riverside County, California is in USDA Zone 9b. The average last spring frost is February 24 and the first fall frost is December 4, giving you a growing season of approximately 283 days.

At an elevation of 1,206 feet, Riverside County receives approximately 15.5 inches of rainfall annually with predominantly loam soil. Summer highs average 102ยฐF, so Patty Pan Squash may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Patty Pan Squash successfully. Mulch heavily to conserve soil moisture.

Riverside County, CA (Zone 9b) Year-round
283 days
Last Spring Frost February 24
283 growing days
First Fall Frost December 4

Riverside County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (212 days to spare)
Start indoors: Jan 6 Transplant: Feb 10 🍅 Harvest: Mar 31 – Apr 28
Recommended (50%) ✓ Fits season (199 days to spare)
Start indoors: Jan 27 Transplant: Mar 3 🍅 Harvest: Apr 21 – May 19
Safe Start (90%) ✓ Fits season (187 days to spare)
Start indoors: Feb 22 Transplant: Mar 29 🍅 Harvest: May 17 – Jun 14

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 Riverside County

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

Soil pH

Your soil pH (6.2โ€“7.8) overlaps with Patty Pan Squash's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

The loam soil in Riverside County is excellent for Patty Pan Squash โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.5%). 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 283-day season

Sow every 5.1 weeks. Last sowing by Oct 05 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.2″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 2,338 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” 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 โ€” 3.5" 0" โ„๏ธ Dormant
Feb 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Mar 4.3" 2.2" 2.1" ๐Ÿ’ง Light watering
Apr 4.3" 1.2" 3.1" ๐Ÿšฟ Regular watering
May 4.3" 0.4" 3.9" ๐Ÿšฟ Regular watering
Jun 4.3" 0.1" 4.2" ๐Ÿšฟ Regular watering
Jul 4.3" 0" 4.3" ๐Ÿšฟ Regular watering
Aug 4.3" 0" 4.3" ๐Ÿšฟ Regular watering
Sep 4.3" 0.2" 4.1" ๐Ÿšฟ Regular watering
Oct 4.3" 0.6" 3.7" ๐Ÿšฟ Regular watering
Nov 4.3" 1.5" 2.8" ๐Ÿšฟ Regular watering
Dec 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering

Water needs are for active growing months only (Febโ€“Dec in Riverside County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,391 GDD — county provides 7,526 GDD Excellent fit

Patty Pan Squash Planting Timeline โ€” Riverside County, CA

Patty Pan Squash Planting Calendar

Activity When Date Range
Start Indoors January 27 Jan 27 โ€“ Feb 10
Transplant Outdoors March 3 Mar 3 โ€“ Mar 17
Direct Sow February 24 Feb 24 โ€“ Mar 17
Harvest April 21 Apr 21 โ€“ May 19

Plant 1" deep ยท 30" apart ยท 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 โ€”
July โ€”
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

45โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 9b

๐Ÿ“† Growing Season

283 days in Riverside County

Growing Tips for Patty Pan Squash in Riverside County

Direct sow Patty Pan Squash outdoors after February 24 in Riverside County when soil has warmed and frost danger has passed.

With summer highs reaching 102ยฐF in Riverside County, provide afternoon shade for Patty Pan Squash and water deeply in the morning.

Your generous 284.0-day season in Riverside 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.

Riverside County receives only 16" of rain annually. Patty Pan Squash needs consistent moisture โ€” 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 Riverside County, CA?

Riverside County is in Zone 9b with an average last frost of February 24. Plan your Patty Pan Squash planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Riverside County, CA?

Riverside County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 24 and first fall frost is December 4.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Riverside County gardeners in Zone 9b organize planting dates, track what's growing, and never miss a planting window.

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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 Riverside County, CA. Local conditions may vary. Last updated: April 2026.