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When to Plant Black Beans in Yuma County, AZ

Yuma County, Arizona Zone 10a May

May in the garden — Yuma County, Arizona

Here's what deserves your attention in Yuma County, Arizona this month. Everything below is tailored to Zone 10a and timed around your local frost dates.

Avg. last frost February 10
Avg. first frost December 1
Soil temp (4") 66°F
Watering Critical
Pest pressure High
Daylight 13.7 hrs
  1. Collect black beans at their peak

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

Get ahead of June
  • First harvests: black beans

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Black beans are a warm-season legume producing small, dark, protein-rich beans that are a staple in Latin American and Caribbean cuisines.

Yuma County, Arizona is in USDA Zone 10a. The average last spring frost is February 10 and the first fall frost is December 1, giving you a growing season of approximately 294 days.

At an elevation of 4,781 feet, Yuma County receives approximately 9.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 92°F, providing good warmth for Black Beans during the growing season. Sandy soil warms quickly in spring — great for early planting — but Black Beans will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Black Beans successfully. Mulch heavily to conserve soil moisture.

Yuma County, AZ (Zone 10a) Year-round
294 days
Last Spring Frost February 10
294 growing days
First Fall Frost December 1
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Yuma County Soil Profile

Soil Type

Sandy Loam

Soil pH

6.9-8.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (156 days to spare)
Transplant: Feb 3 🍅 Harvest: May 5 – Jun 23
Recommended (50%) ✓ Fits season (154 days to spare)
Transplant: Feb 10 🍅 Harvest: May 12 – Jun 30
Safe Start (90%) ✓ Fits season (144 days to spare)
Transplant: Mar 9 🍅 Harvest: Jun 8 – Jul 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 Yuma County

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

Soil pH

Your soil pH (6.9–8.4) is more alkaline than Black Beans prefers (6.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Yuma County warms quickly in spring but drains fast. Black Beans will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is low (0.8%). Add 2-3 inches of compost before planting Black Beans.

How to Plant Black Beans

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.1″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 2,729 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Black Beans

Black Beans needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Black Beans Needs Rainfall You Supplement Action
Jan 0.6" 0" ❄️ Dormant
Feb 4.3" 0.5" 3.8" 🚿 Regular watering
Mar 4.3" 0.5" 3.8" 🚿 Regular watering
Apr 4.3" 0.3" 4" 🚿 Regular watering
May 4.3" 0.2" 4.1" 🚿 Regular watering
Jun 4.3" 0.3" 4" 🚿 Regular watering
Jul 4.3" 1.8" 2.5" 🚿 Regular watering
Aug 4.3" 1.9" 2.4" 🚿 Regular watering
Sep 4.3" 1.4" 2.9" 🚿 Regular watering
Oct 4.3" 0.8" 3.5" 🚿 Regular watering
Nov 4.3" 0.5" 3.8" 🚿 Regular watering
Dec 4.3" 0.6" 3.7" 🚿 Regular watering

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

Black 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.

Black Beans needs ~1,995 GDD — county provides 5,605 GDD Excellent fit

Black Beans Planting Timeline — Yuma County, AZ

Black Beans Planting Calendar

Activity When Date Range
Direct Sow February 17 Feb 17 – Mar 10
Harvest May 19 May 19 – Jul 7

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

Month-by-Month Timeline

MonthActivities
January
February Direct Sow
March Direct Sow
April
May Harvest
June Harvest
July Harvest
August
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 10a

📆 Growing Season

294 days in Yuma County

Growing Tips for Black Beans in Yuma County

Direct sow Black Beans outdoors after February 10 in Yuma County when soil has warmed and frost danger has passed.

Sandy soil in Yuma County dries quickly — mulch Black Beans with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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

Yuma County receives only 9" of rain annually. Black Beans needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after last frost. Provide support for climbing varieties. Allow pods to dry fully on the vine before harvesting. Thresh dried pods by hand or in a pillowcase.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Black Beans in Yuma County, AZ?

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

What planting zone is Yuma County, AZ?

Yuma County, Arizona is in USDA Hardiness Zone 10a. The average last spring frost is February 10 and first fall frost is December 1.

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Your Yuma County Garden Planner — Free

A 24-page printable planner built for Yuma 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.

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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 Yuma County, AZ. 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.