Blog

When to Plant Lima Beans in Douglas County, OR

Douglas County, Oregon Zone 8b May

Top priorities for Douglas County, Oregon gardeners in May

Welcome to May in Zone 8b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 4
Avg. first frost November 5
Soil temp (4") 73°F
Watering Moderate
Pest pressure High
Daylight 14.5 hrs
Get ahead of June
  • First harvests: lima beans

Instant PDF download. No spam, unsubscribe any time.

Lima beans are a warm-season legume producing large, creamy beans with a buttery texture. Both bush and pole varieties are available, with pole types yielding more.

Douglas County, Oregon is in USDA Zone 8b. The average last spring frost is April 4 and the first fall frost is November 5, giving you a growing season of approximately 215 days.

At an elevation of 377 feet, Douglas County receives approximately 52.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Lima Beans during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Lima Beans root diseases.

Douglas County, OR (Zone 8b) Long season
215 days
Last Spring Frost April 4
215 growing days
First Fall Frost November 5

Douglas County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (106 days to spare)
Transplant: Mar 28 🍅 Harvest: May 30 – Jul 11
Recommended (50%) ✓ Fits season (110 days to spare)
Transplant: Apr 4 🍅 Harvest: Jun 6 – Jul 18
Safe Start (90%) ✓ Fits season (116 days to spare)
Transplant: Apr 30 🍅 Harvest: Jul 2 – Aug 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 Douglas County

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

Soil pH

Your soil pH (5.8–6.4) overlaps with Lima Beans's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.4%) — Lima Beans will thrive.

How to Plant Lima Beans

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

Succession Planting Lima Beans

4
successive plantings in your 215-day season

Sow every 6.9 weeks. Last sowing by Aug 07 to harvest before frost.

Plant Water Budget

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

Monthly Watering Guide for Lima Beans

Lima Beans needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.

Month Lima Beans Needs Rainfall You Supplement Action
Jan 8.6" 0" ❄️ Dormant
Feb 6.2" 0" ❄️ Dormant
Mar 4.9" 0" ❄️ Dormant
Apr 3.9" 4.3" 0" ✅ Rainfall sufficient
May 3.9" 3.4" 0.5" 💧 Light watering
Jun 3.9" 2.3" 1.6" 💧 Light watering
Jul 3.9" 0.8" 3.1" 🚿 Regular watering
Aug 3.9" 1" 2.9" 🚿 Regular watering
Sep 3.9" 2.2" 1.7" 💧 Light watering
Oct 3.9" 4" 0" ✅ Rainfall sufficient
Nov 3.9" 7.6" 0" ✅ Rainfall sufficient
Dec 7.4" 0" ❄️ Dormant

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

Lima 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.

Lima Beans needs ~1,312 GDD — county provides 3,762 GDD Excellent fit

Lima Beans Planting Timeline — Douglas County, OR

Lima Beans Planting Calendar

Activity When Date Range
Direct Sow April 11 Apr 11 – May 2
Harvest June 13 Jun 13 – Jul 25

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
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

215 days in Douglas County

Growing Tips for Lima Beans in Douglas County

Direct sow Lima Beans outdoors after April 04 in Douglas County when soil has warmed and frost danger has passed.

Common pests for Lima 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 soil is thoroughly warm at 65F or above. Do not soak seeds before planting as they may crack. Harvest when pods are plump but still green for fresh limas.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic
  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lima Beans in Douglas County, OR?

Douglas County is in Zone 8b with an average last frost of April 4. Plan your Lima Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Douglas County, OR?

Douglas County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 4 and first fall frost is November 5.

🌱

Your Douglas County Garden Planner — Free

A 24-page printable planner built for Douglas County (Zone 8b). 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 Douglas 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.