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When to Plant Eggplant in Douglas County, WA

Douglas County, Washington Zone 7a May

Your May game plan for Douglas County, Washington

Each item below is timed to Douglas County, Washington's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 8
Avg. first frost October 4
Soil temp (4") 54°F
Watering Critical
Pest pressure Low
Daylight 14.9 hrs
  1. Get eggplant in the ground

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

  2. Outdoor sowing time: eggplant

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

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Eggplant is a heat-loving solanaceous crop that produces glossy fruits in purple, white, or striped varieties. It requires long, warm growing seasons for best production.

Douglas County, Washington is in USDA Zone 7a. The average last spring frost is May 8 and the first fall frost is October 4, giving you a growing season of approximately 149 days.

At an elevation of 2,920 feet, Douglas County receives approximately 15.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Eggplant during the growing season. With low rainfall, drip irrigation is essential for growing Eggplant successfully. Mulch heavily to conserve soil moisture.

Douglas County, WA (Zone 7a) Short season
149 days
Last Spring Frost May 8
149 growing days
First Fall Frost October 4
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Douglas County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (13 days to spare)
Start indoors: Feb 15 Transplant: May 3 🍅 Harvest: Jul 12 – Sep 13
Recommended (50%) ✓ Fits season (2 days to spare)
Start indoors: Mar 6 Transplant: May 22 🍅 Harvest: Jul 31 – Oct 2
Safe Start (90%) ✗ May not fit
Start indoors: Apr 8 Transplant: Jun 24 🍅 Harvest: Sep 2 – Nov 4

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 Eggplant's growing requirements.

Soil pH

Your soil pH (5.5–6.2) is within Eggplant's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (5.5%) — Eggplant will thrive.

How to Plant Eggplant

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Eggplant

2
successive plantings in your 149-day season

Sow every 7.4 weeks. Last sowing by Jul 11 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.5″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,042 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Eggplant

Eggplant needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.

Month Eggplant Needs Rainfall You Supplement Action
Jan 2.2" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 1.2" 0" ❄️ Dormant
May 4.8" 0.8" 4" 🚿 Regular watering
Jun 4.8" 0.6" 4.2" 🚿 Regular watering
Jul 4.8" 0.2" 4.6" 🚿 Regular watering
Aug 4.8" 0.3" 4.5" 🚿 Regular watering
Sep 4.8" 0.7" 4.1" 🚿 Regular watering
Oct 4.8" 1.2" 3.6" 🚿 Regular watering
Nov 2.5" 0" ❄️ Dormant
Dec 2.7" 0" ❄️ Dormant

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

Eggplant 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.

Eggplant needs ~1,312 GDD — county provides 2,607 GDD Excellent fit

Eggplant Planting Timeline — Douglas County, WA

Eggplant Planting Calendar

Activity When Date Range
Start Indoors March 6 Mar 6 – Mar 20
Transplant Outdoors May 22 May 22 – Jun 5
Direct Sow May 15 May 15 – Jun 5
Harvest July 31 Jul 31 – Oct 2

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July Harvest
August Harvest
September Harvest
October Harvest
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · 2-3 times/week

📅 Days to Maturity

65–85 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 7a

📆 Growing Season

149 days in Douglas County

Growing Tips for Eggplant in Douglas County

Direct sow Eggplant outdoors after May 08 in Douglas County when soil has warmed and frost danger has passed.

Common pests for Eggplant in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.

Douglas County receives only 16" of rain annually. Eggplant needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 8-10 weeks before last frost. Transplant only after nighttime temperatures stay above 55F. Mulch to retain moisture and warmth around roots.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel
  • Kohlrabi

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Eggplant in Douglas County, WA?

Douglas County is in Zone 7a with an average last frost of May 8. Plan your Eggplant planting based on this frost date — see the calendar above for exact timing.

What planting zone is Douglas County, WA?

Douglas County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is May 8 and first fall frost is October 4.

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Your Douglas County Garden Planner — Free

A 24-page printable planner built for Douglas 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.

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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 Douglas County, WA. 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.