Blog

When to Plant Black Beans in Polk County, AR

Polk County, Arkansas Zone 8a May

Top priorities for Polk County, Arkansas gardeners in May

Each item below is timed to Polk County, Arkansas's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 2
Avg. first frost November 3
Soil temp (4") 67°F
Watering Low
Pest pressure Moderate
Daylight 13.8 hrs

Instant PDF download. No spam, unsubscribe any time.

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

Polk County, Arkansas is in USDA Zone 8a. The average last spring frost is April 2 and the first fall frost is November 3, giving you a growing season of approximately 215 days.

At an elevation of 1,323 feet, Polk County receives approximately 54.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Black Beans during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Black Beans root diseases.

Polk County, AR (Zone 8a) Long season
215 days
Last Spring Frost April 2
215 growing days
First Fall Frost November 3
Share this guide:

Polk County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (81 days to spare)
Transplant: Mar 21 🍅 Harvest: Jun 20 – Aug 8
Recommended (50%) ✓ Fits season (75 days to spare)
Transplant: Apr 2 🍅 Harvest: Jul 2 – Aug 20
Safe Start (90%) ✓ Fits season (84 days to spare)
Transplant: Apr 15 🍅 Harvest: Jul 15 – Sep 2

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 Polk County

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

Soil pH

Your soil pH (5.4–6.6) overlaps with Black Beans's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Polk County is excellent for Black Beans — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help 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
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 4.5" 0" ❄️ Dormant
Feb 5" 0" ❄️ Dormant
Mar 4.8" 0" ❄️ Dormant
Apr 4.3" 4" 0.3" 💧 Light watering
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 4.8" 0" ✅ Rainfall sufficient
Jul 4.3" 5.6" 0" ✅ Rainfall sufficient
Aug 4.3" 4.7" 0" ✅ Rainfall sufficient
Sep 4.3" 4.6" 0" ✅ Rainfall sufficient
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 4.3" 4.4" 0" ✅ Rainfall sufficient
Dec 4.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Polk 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 ~1,916 GDD — county provides 3,923 GDD Excellent fit

Black Beans Planting Timeline — Polk County, AR

Black Beans Planting Calendar

Activity When Date Range
Direct Sow April 9 Apr 9 – Apr 30
Harvest July 9 Jul 9 – Aug 27

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

215 days in Polk County

Growing Tips for Black Beans in Polk County

Direct sow Black Beans outdoors after April 02 in Polk County when soil has warmed and frost danger has passed.

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

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 Polk County, AR?

Polk County is in Zone 8a with an average last frost of April 2. Plan your Black Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Polk County, AR?

Polk County, Arkansas is in USDA Hardiness Zone 8a. The average last spring frost is April 2 and first fall frost is November 3.

🌱

Your Polk County Garden Planner — Free

A 24-page printable planner built for Polk County (Zone 8a). 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 Polk County, AR. 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.