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When to Plant Lima Beans in San Joaquin County, CA

San Joaquin County, California Zone 9b May

Top priorities for San Joaquin County, California gardeners in May

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

Avg. last frost February 4
Avg. first frost December 6
Soil temp (4") 77°F
Watering Critical
Pest pressure High
Daylight 14 hrs
  1. Bring in the lima beans

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

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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.

San Joaquin County, California is in USDA Zone 9b. The average last spring frost is February 4 and the first fall frost is December 6, giving you a growing season of approximately 305 days.

At an elevation of 220 feet, San Joaquin County receives approximately 15 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Lima Beans during the growing season. With low rainfall, drip irrigation is essential for growing Lima Beans successfully. Mulch heavily to conserve soil moisture.

San Joaquin County, CA (Zone 9b) Year-round
305 days
Last Spring Frost February 4
305 growing days
First Fall Frost December 6
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San Joaquin County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (210 days to spare)
Transplant: Jan 18 🍅 Harvest: Mar 22 – May 3
Recommended (50%) ✓ Fits season (200 days to spare)
Transplant: Feb 4 🍅 Harvest: Apr 8 – May 20
Safe Start (90%) ✓ Fits season (184 days to spare)
Transplant: Mar 5 🍅 Harvest: May 7 – Jun 18

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 San Joaquin County

How your county's soil matches Lima Beans's growing requirements.

Soil pH

Your soil pH (6.4–7.8) is more alkaline than Lima Beans prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in San Joaquin County is excellent for Lima Beans — 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

6
successive plantings in your 305-day season

Sow every 6.9 weeks. Last sowing by Sep 07 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 2,268 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 2.9" 0" ❄️ Dormant
Feb 3.9" 3.1" 0.8" 💧 Light watering
Mar 3.9" 2.6" 1.3" 💧 Light watering
Apr 3.9" 1.2" 2.7" 🚿 Regular watering
May 3.9" 0.4" 3.5" 🚿 Regular watering
Jun 3.9" 0.1" 3.8" 🚿 Regular watering
Jul 3.9" 0" 3.9" 🚿 Regular watering
Aug 3.9" 0" 3.9" 🚿 Regular watering
Sep 3.9" 0.2" 3.7" 🚿 Regular watering
Oct 3.9" 0.7" 3.2" 🚿 Regular watering
Nov 3.9" 1.3" 2.6" 🚿 Regular watering
Dec 3.9" 2.6" 1.3" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in San Joaquin County). Supplement amounts are based on average rainfall — 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" — 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.

Lima Beans needs ~1,481 GDD — county provides 6,043 GDD Excellent fit

Lima Beans Planting Timeline — San Joaquin County, CA

Lima Beans Planting Calendar

Activity When Date Range
Direct Sow February 11 Feb 11 – Mar 4
Harvest April 15 Apr 15 – May 27

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

Month-by-Month Timeline

MonthActivities
January
February Direct Sow
March 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

0.9"/week · 2-3 times/week

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

305 days in San Joaquin County

Growing Tips for Lima Beans in San Joaquin County

Direct sow Lima Beans outdoors after February 04 in San Joaquin County when soil has warmed and frost danger has passed.

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

San Joaquin County receives only 15" of rain annually. Lima Beans needs consistent moisture — 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 San Joaquin County, CA?

San Joaquin County is in Zone 9b with an average last frost of February 4. Plan your Lima Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is San Joaquin County, CA?

San Joaquin County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 4 and first fall frost is December 6.

🌱

Your San Joaquin County Garden Planner — Free

A 24-page printable planner built for San Joaquin 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 San Joaquin 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.