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When to Plant Kidney Beans in Benton County, WA

Kidney beans are a popular dry bean variety named for their shape, available in red and white types. They are the classic bean for chili and red beans and rice.

Benton County, Washington is in USDA Zone 7a. The average last spring frost is April 3 and the first fall frost is October 27, giving you a growing season of approximately 207 days.

At an elevation of 2,633 feet, Benton County receives approximately 22.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Kidney Beans during the growing season.

Benton County, WA (Zone 7a) Long season
207 days
Last Spring Frost April 3
207 growing days
First Fall Frost October 27

Benton County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (86 days to spare)
Transplant: Mar 24 🍅 Harvest: Jun 23 – Jul 28
Recommended (50%) ✓ Fits season (81 days to spare)
Transplant: Apr 3 🍅 Harvest: Jul 3 – Aug 7
Safe Start (90%) ✓ Fits season (78 days to spare)
Transplant: Apr 20 🍅 Harvest: Jul 20 – Aug 24

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 1,001 gal / 100 sq ft
Kidney Beans needs ~1,560 GDD — county provides 3,312 GDD Excellent fit

Kidney Beans Planting Timeline โ€” Benton County, WA

Kidney Beans Planting Calendar

Activity When Date Range
Direct Sow April 10 Apr 10 โ€“ May 1
Harvest July 10 Jul 10 โ€“ Aug 14

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Direct Sow
May Direct Sow
June โ€”
July Harvest
August Harvest
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

85โ€“110 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 7a

Growing Season

207 days

Growing Tips for Benton County

Direct sow after frost. Allow pods to dry completely on the plant. Kidney beans must be thoroughly cooked as raw or undercooked beans contain harmful lectins.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Level Up Your Garden

Frequently Asked Questions

When should I plant Kidney Beans in Benton County, WA?

Benton County is in Zone 7a with an average last frost of April 3. Plan your Kidney Beans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Benton County, WA?

Benton County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is April 3 and first fall frost is October 27.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Benton County gardeners in Zone 7a 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 Benton County, WA. Local conditions may vary. Last updated: April 2026.