Blog

When to Plant Wax Beans in Umatilla County, OR

Umatilla County, Oregon Zone 7a May

Umatilla County, Oregon gardeners: here's your May plan

Welcome to May in Zone 7a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 23
Avg. first frost October 20
Soil temp (4") 60°F
Watering Critical
Pest pressure Low
Daylight 14.7 hrs
June will be here before you know it — start on
  • First harvests: wax beans

Instant PDF download. No spam, unsubscribe any time.

Wax beans are a yellow-podded variety of snap beans with a buttery, slightly sweeter flavor than green beans. They are easy to spot on the plant for picking.

Umatilla County, 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 Wax Beans during the growing season. With low rainfall, drip irrigation is essential for growing Wax Beans successfully. Mulch heavily to conserve soil moisture.

Umatilla County, OR (Zone 7a) Moderate season
180 days
Last Spring Frost April 23
180 growing days
First Fall Frost October 20

Umatilla County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (72 days to spare)
Transplant: Apr 8 🍅 Harvest: Jun 3 – Jul 29
Recommended (50%) ✓ Fits season (68 days to spare)
Transplant: Apr 23 🍅 Harvest: Jun 18 – Aug 13
Safe Start (90%) ✓ Fits season (67 days to spare)
Transplant: May 13 🍅 Harvest: Jul 8 – 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 Umatilla County

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

Soil pH

Your soil pH (5.2–6.8) overlaps with Wax Beans's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.1%) — Wax Beans will thrive.

How to Plant Wax Beans

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

Succession Planting Wax Beans

4
successive plantings in your 180-day season

Sow every 5.7 weeks. Last sowing by Aug 16 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.3″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,056 gal / 100 sq ft

Monthly Watering Guide for Wax Beans

Wax 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 Wax 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.

Wax 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.

Wax Beans needs ~834 GDD — county provides 2,610 GDD Excellent fit

Wax Beans Planting Timeline — Umatilla County, OR

Wax Beans Planting Calendar

Activity When Date Range
Direct Sow April 30 Apr 30 – May 21
Harvest June 25 Jun 25 – Aug 20

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

50–65 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

180 days in Umatilla County

Growing Tips for Wax Beans in Umatilla County

Direct sow Wax Beans outdoors after April 23 in Umatilla County when soil has warmed and frost danger has passed.

Common pests for Wax 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. Wax Beans needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after last frost. Pick pods regularly when young and tender. Bush types produce a concentrated harvest while pole types yield longer. Avoid working around wet plants.

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 Wax Beans in Umatilla County, OR?

Umatilla County is in Zone 7a with an average last frost of April 23. Plan your Wax Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Umatilla County, OR?

Umatilla County, Oregon is in USDA Hardiness Zone 7a. The average last spring frost is April 23 and first fall frost is October 20.

🌱

Your Umatilla County Garden Planner — Free

A 24-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.

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 Umatilla County, OR. 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.