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When to Plant Lima Beans in Riverside County, CA

Lima beans are a warm-season legume producing large, creamy beans with a buttery texture. Both bush and pole varieties are available, with pole types yielding more.

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 Lima Beans may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Lima Beans 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 (191 days to spare)
Transplant: Feb 3 🍅 Harvest: Apr 7 – May 19
Recommended (50%) ✓ Fits season (178 days to spare)
Transplant: Feb 24 🍅 Harvest: Apr 28 – Jun 9
Safe Start (90%) ✓ Fits season (166 days to spare)
Transplant: Mar 22 🍅 Harvest: May 24 – Jul 5

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 Lima Beans's growing requirements.

Soil pH

Your soil pH (6.2โ€“7.8) overlaps with Lima Beans's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Lima Beans.

How to Plant Lima Beans

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Succession Planting Lima Beans

5
successive plantings in your 283-day season

Sow every 6.9 weeks. Last sowing by Sep 05 to harvest before frost.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.2″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 2,035 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Lima Beans

Lima Beans needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.

Month Lima Beans Needs Rainfall You Supplement Action
Jan โ€” 3.5" 0" โ„๏ธ Dormant
Feb 3.9" 3.6" 0.3" ๐Ÿ’ง Light watering
Mar 3.9" 2.2" 1.7" ๐Ÿ’ง Light watering
Apr 3.9" 1.2" 2.7" ๐Ÿšฟ Regular watering
May 3.9" 0.4" 3.5" ๐Ÿšฟ Regular watering
Jun 3.9" 0.1" 3.8" ๐Ÿšฟ Regular watering
Jul 3.9" 0" 3.9" ๐Ÿšฟ Regular watering
Aug 3.9" 0" 3.9" ๐Ÿšฟ Regular watering
Sep 3.9" 0.2" 3.7" ๐Ÿšฟ Regular watering
Oct 3.9" 0.6" 3.3" ๐Ÿšฟ Regular watering
Nov 3.9" 1.5" 2.4" ๐Ÿšฟ Regular watering
Dec 3.9" 2.4" 1.5" 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.

Lima Beans 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.

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

Lima Beans Planting Timeline โ€” Riverside County, CA

Lima Beans Planting Calendar

Activity When Date Range
Direct Sow March 3 Mar 3 โ€“ Mar 24
Harvest May 5 May 5 โ€“ Jun 16

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Direct Sow
April โ€”
May Harvest
June Harvest
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

0.9"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 9b

๐Ÿ“† Growing Season

283 days in Riverside County

Growing Tips for Lima Beans in Riverside County

Direct sow Lima Beans 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 Lima Beans and water deeply in the morning.

Common pests for Lima Beans in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

Riverside County receives only 16" of rain annually. Lima Beans needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after soil is thoroughly warm at 65F or above. Do not soak seeds before planting as they may crack. Harvest when pods are plump but still green for fresh limas.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic
  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lima Beans in Riverside County, CA?

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