Blog

When to Plant Green Beans in San Bernardino County, CA

San Bernardino County, California Zone 10a May

Your May planting checklist for San Bernardino County, California

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

Avg. last frost February 24
Avg. first frost November 25
Soil temp (4") 78°F
Watering Critical
Pest pressure High
Daylight 13.8 hrs
  1. It's harvest week for green beans

    If you can't use it all right away, check the food-preservation section of your planner.

June will be here before you know it — start on
  • First harvests: green beans

Instant PDF download. No spam, unsubscribe any time.

Green beans are a warm-season staple available as bush or pole types. Bush beans produce a concentrated harvest while pole beans provide a longer picking season.

San Bernardino County, California is in USDA Zone 10a. The average last spring frost is February 24 and the first fall frost is November 25, giving you a growing season of approximately 274 days.

At an elevation of 1,012 feet, San Bernardino County receives approximately 16.9 inches of rainfall annually with predominantly loam soil. Summer highs average 97°F, so Green Beans may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Green Beans successfully. Mulch heavily to conserve soil moisture.

San Bernardino County, CA (Zone 10a) Year-round
274 days
Last Spring Frost February 24
274 growing days
First Fall Frost November 25
Share this guide:

San Bernardino County Soil Profile

Soil Type

Loam

Soil pH

5.9-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (168 days to spare)
Transplant: Feb 13 🍅 Harvest: Apr 10 – Jun 5
Recommended (50%) ✓ Fits season (162 days to spare)
Transplant: Feb 24 🍅 Harvest: Apr 21 – Jun 16
Safe Start (90%) ✓ Fits season (165 days to spare)
Transplant: Mar 7 🍅 Harvest: May 2 – Jun 27

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 Bernardino County

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

Soil pH

Your soil pH (5.9–7.2) overlaps with Green Beans's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in San Bernardino County is excellent for Green Beans — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Green Beans.

How to Plant Green Beans

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

Succession Planting Green Beans

6
successive plantings in your 274-day season

Sow every 5.7 weeks. Last sowing by Sep 21 to harvest before frost.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.3″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,885 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Green Beans

Green 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 Green Beans Needs Rainfall You Supplement Action
Jan 3.2" 0" ❄️ Dormant
Feb 3.9" 3.8" 0.1" 💧 Light watering
Mar 3.9" 2.2" 1.7" 💧 Light watering
Apr 3.9" 1.5" 2.4" 🚿 Regular watering
May 3.9" 0.5" 3.4" 🚿 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" 1.7" 2.2" 🚿 Regular watering
Dec 3" 0" ❄️ Dormant

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

Green 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.

Green Beans needs ~1,308 GDD — county provides 6,256 GDD Excellent fit

Green Beans Planting Timeline — San Bernardino County, CA

Green Beans Planting Calendar

Activity When Date Range
Direct Sow March 3 Mar 3 – Mar 24
Harvest April 28 Apr 28 – Jun 23

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

Month-by-Month Timeline

MonthActivities
January
February
March Direct Sow
April Harvest
May Harvest
June Harvest
July
August
September
October
November
December
Share this guide:

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · 2-3 times/week

📅 Days to Maturity

50–65 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 10a

📆 Growing Season

274 days in San Bernardino County

Growing Tips for Green Beans in San Bernardino County

Direct sow Green Beans outdoors after February 24 in San Bernardino County when soil has warmed and frost danger has passed.

With summer highs reaching 97°F in San Bernardino County, provide afternoon shade for Green Beans and water deeply in the morning.

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

San Bernardino County receives only 17" of rain annually. Green Beans needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after last frost when soil is warm. Provide sturdy supports for pole varieties. Pick beans regularly when young and tender to encourage continued production.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic
  • Fennel

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Green Beans Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Allow pods to dry fully on vine until they rattle.
Storage Store airtight; viable 4 years at 35°F, under 45% humidity.

Avoid harvesting during damp weather. Isolate 25 ft between varieties.

Frequently Asked Questions

When should I plant Green Beans in San Bernardino County, CA?

San Bernardino County is in Zone 10a with an average last frost of February 24. Plan your Green Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is San Bernardino County, CA?

San Bernardino County, California is in USDA Hardiness Zone 10a. The average last spring frost is February 24 and first fall frost is November 25.

🌱

Your San Bernardino County Garden Planner — Free

A 24-page printable planner built for San Bernardino County (Zone 10a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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