When to Plant Black Beans in Pendleton, OR
Top priorities for Umatilla County, Oregon gardeners in August
August is a pivotal month for Umatilla County, Oregon gardens. Focus on these tasks first and you'll set up the rest of the season for success.
Black beans are a warm-season legume producing small, dark, protein-rich beans that are a staple in Latin American and Caribbean cuisines.
Pendleton, Oregon is in USDA Zone 7a. The average last spring frost is April 23 and the first fall frost is October 20, giving you a growing season of approximately 180 days.
At an elevation of 2,195 feet, Umatilla County receives approximately 14.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Black Beans during the growing season. With low rainfall, drip irrigation is essential for growing Black Beans successfully. Mulch heavily to conserve soil moisture.
Pendleton Soil Profile
Soil Type
Silt Loam
Soil pH
5.2-6.8
Drainage
Well Drained
Black Beans Planting Risk Windows
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 Pendleton
How your county's soil matches Black Beans's growing requirements.
Soil pH
Your soil pH (5.2–6.8) overlaps with Black Beans's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Umatilla County is excellent for Black Beans — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.1%) — Black Beans will thrive.
How to Plant Black Beans
Black Beans Water Budget
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 | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 1.8" | 0" | ❄️ Dormant |
| Mar | — | 1.3" | 0" | ❄️ Dormant |
| Apr | 4.3" | 1.1" | 3.2" | 🚿 Regular watering |
| May | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Jun | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Jul | 4.3" | 0.3" | 4" | 🚿 Regular watering |
| Aug | 4.3" | 0.3" | 4" | 🚿 Regular watering |
| Sep | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Oct | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 2.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Umatilla 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 Planting Timeline — Pendleton, OR
Black Beans Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 30 | Apr 30 – May 21 |
| Harvest | July 30 | Jul 30 – Sep 17 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Direct Sow |
| May | Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 7a
📆 Growing Season
180 days in Umatilla County
Growing Tips for Black Beans in Pendleton
Direct sow Black Beans outdoors after April 23 in Umatilla 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.
Umatilla County receives only 15" 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
Check more plant combinations with our Companion Planting Checker →
Black Beans in Other Locations
Your Umatilla County Garden Planner — Free
A 22-page printable planner built for Umatilla County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.