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When to Plant Soybeans in Deschutes County, OR

Deschutes County, Oregon Zone 6b May

Your May gardening checklist

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Deschutes County, Oregon.

Avg. last frost June 15
Avg. first frost September 13
Soil temp (4") 62°F
Watering Moderate
Pest pressure Low
Daylight 14.5 hrs
June prep starts now
  • Direct-sowing: soybeans

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Soybeans (edamame) are a high-protein legume that fixes nitrogen in the soil. Fresh green soybeans harvested at the edamame stage are a nutritious snack.

Deschutes County, Oregon is in USDA Zone 6b. The average last spring frost is June 15 and the first fall frost is September 13, giving you a growing season of approximately 90 days.

At an elevation of 221 feet, Deschutes County receives approximately 54.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Soybeans to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Soybeans root diseases.

Deschutes County, OR (Zone 6b) Very short season
90 days
Last Spring Frost June 15
90 growing days
First Fall Frost September 13

Deschutes County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Jun 3 🍅 Harvest: Aug 26 – Oct 21
Recommended (50%) ✗ May not fit
Transplant: Jun 15 🍅 Harvest: Sep 7 – Nov 2
Safe Start (90%) ✗ May not fit
Transplant: Jun 26 🍅 Harvest: Sep 18 – Nov 13

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 Deschutes County

How your county's soil matches Soybeans's growing requirements.

Soil pH

Your soil pH (5.4–6.2) is more acidic than Soybeans prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.0%) — Soybeans will thrive.

How to Plant Soybeans

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
2.6″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Soybeans

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

Month Soybeans Needs Rainfall You Supplement Action
Jan 7.6" 0" ❄️ Dormant
Feb 6.2" 0" ❄️ Dormant
Mar 4.9" 0" ❄️ Dormant
Apr 3.8" 0" ❄️ Dormant
May 3" 0" ❄️ Dormant
Jun 4.3" 2.5" 1.8" 💧 Light watering
Jul 4.3" 1" 3.3" 🚿 Regular watering
Aug 4.3" 1" 3.3" 🚿 Regular watering
Sep 4.3" 2.2" 2.1" 💧 Light watering
Oct 4.9" 0" ❄️ Dormant
Nov 7.8" 0" ❄️ Dormant
Dec 9.9" 0" ❄️ Dormant

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

Soybeans 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.

Soybeans needs ~1,075 GDD — county provides 967 GDD May not mature

Soybeans Planting Timeline — Deschutes County, OR

Soybeans Planting Calendar

Activity When Date Range
Direct Sow June 22 Jun 22 – Jul 13
Harvest September 14 Sep 14 – Nov 9

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

90 days in Deschutes County

Growing Tips for Soybeans in Deschutes County

Direct sow Soybeans outdoors after June 15 in Deschutes County when soil has warmed and frost danger has passed.

Your 90.0-day growing season in Deschutes County is tight for Soybeans (80.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Soybeans 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 soil warms to 60F. Plant in blocks rather than rows for better pollination. Harvest for edamame when pods are plump and bright green.

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 Soybeans in Deschutes County, OR?

Deschutes County is in Zone 6b with an average last frost of June 15. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Deschutes County, OR?

Deschutes County, Oregon is in USDA Hardiness Zone 6b. The average last spring frost is June 15 and first fall frost is September 13.

🌱

Your Deschutes County Garden Planner — Free

A 24-page printable planner built for Deschutes County (Zone 6b). 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 Deschutes 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.