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When to Plant Peppers in Riverside County, CA

Sweet peppers are warm-season crops producing fruits in a rainbow of colors. They turn from green to red, yellow, or orange as they ripen, increasing in sweetness.

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 Peppers may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Peppers 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 (156 days to spare)
Start indoors: Dec 23 Transplant: Feb 10 🍅 Harvest: Apr 14 – Jun 23
Recommended (50%) ✓ Fits season (143 days to spare)
Start indoors: Jan 13 Transplant: Mar 3 🍅 Harvest: May 5 – Jul 14
Safe Start (90%) ✓ Fits season (131 days to spare)
Start indoors: Feb 8 Transplant: Mar 29 🍅 Harvest: May 31 – Aug 9

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.

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

Peppers needs ~1,988 GDD — county provides 7,526 GDD Excellent fit

Peppers Planting Timeline โ€” Riverside County, CA

Peppers Planting Calendar

Activity When Date Range
Start Indoors January 13 Jan 13 โ€“ Jan 27
Transplant Outdoors March 3 Mar 3 โ€“ Mar 17
Direct Sow February 24 Feb 24 โ€“ Mar 17
Harvest May 5 May 5 โ€“ Jul 14

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“90 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 9b

Growing Season

283 days

Growing Tips for Riverside County

Start seeds indoors 8-10 weeks before last frost. Transplant when nighttime temperatures stay above 55F. Avoid high-nitrogen fertilizers which promote leaves over fruit.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel
  • Kohlrabi

Level Up Your Garden

๐ŸŒพ Save Your Own Peppers Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Remove seeds from fully ripe (red/orange) fruit.
Storage Store airtight; viable 4 years at 35ยฐF, under 50% humidity.

Isolate 300 ft for purity. Hot and sweet peppers can cross-pollinate.

Frequently Asked Questions

When should I plant Peppers in Riverside County, CA?

Riverside County is in Zone 9b with an average last frost of February 24. Plan your Peppers 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.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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.