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When to Plant Eggplant in Door County, WI

Door County, Wisconsin Zone 5b May

Top priorities for Door County, Wisconsin gardeners in May

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 11
Avg. first frost October 8
Soil temp (4") 58°F
Watering Low
Pest pressure Low
Daylight 14.6 hrs
  1. Transplant eggplant outside

    Your last frost (May 11) has passed. These warm-season crops can handle outdoor soil now.

  2. Plant eggplant from seed, right in the garden

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

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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.

Door County, Wisconsin is in USDA Zone 5b. The average last spring frost is May 11 and the first fall frost is October 8, giving you a growing season of approximately 150 days.

At an elevation of 564 feet, Door County receives approximately 41.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Eggplant during the growing season.

Door County, WI (Zone 5b) Moderate season
150 days
Last Spring Frost May 11
150 growing days
First Fall Frost October 8

Door County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (4 days to spare)
Start indoors: Feb 24 Transplant: May 19 🍅 Harvest: Jul 28 – Sep 29
Recommended (50%) ✓ Fits season (3 days to spare)
Start indoors: Mar 2 Transplant: May 25 🍅 Harvest: Aug 3 – Oct 5
Safe Start (90%) ✓ Fits season (5 days to spare)
Start indoors: Mar 17 Transplant: Jun 9 🍅 Harvest: Aug 18 – Oct 20

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 Door County

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

Soil pH

Your soil pH (6.0–7.3) overlaps with Eggplant's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Eggplant.

Organic Matter

Organic matter is excellent (4.7%) — Eggplant will thrive.

How to Plant Eggplant

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

Succession Planting Eggplant

2
successive plantings in your 150-day season

Sow every 7.4 weeks. Last sowing by Jul 15 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
1.2″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 416 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 1.7" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 3.4" 0" ❄️ Dormant
May 4.8" 4.6" 0.2" 💧 Light watering
Jun 4.8" 5.7" 0" ✅ Rainfall sufficient
Jul 4.8" 4.7" 0.1" 💧 Light watering
Aug 4.8" 4.4" 0.4" 💧 Light watering
Sep 4.8" 3.7" 1.1" 💧 Light watering
Oct 4.8" 3.6" 1.2" 💧 Light watering
Nov 3.2" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Door 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 ~1,144 GDD — county provides 2,287 GDD Excellent fit

Eggplant Planting Timeline — Door County, WI

Eggplant Planting Calendar

Activity When Date Range
Start Indoors March 2 Mar 2 – Mar 16
Transplant Outdoors May 25 May 25 – Jun 8
Direct Sow May 18 May 18 – Jun 8
Harvest August 3 Aug 3 – Oct 5

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
August Harvest
September Harvest
October Harvest
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · 1-2 times/week

📅 Days to Maturity

65–85 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

150 days in Door County

Growing Tips for Eggplant in Door County

Direct sow Eggplant outdoors after May 11 in Door 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.

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 Door County, WI?

Door County is in Zone 5b with an average last frost of May 11. Plan your Eggplant planting based on this frost date — see the calendar above for exact timing.

What planting zone is Door County, WI?

Door County, Wisconsin is in USDA Hardiness Zone 5b. The average last spring frost is May 11 and first fall frost is October 8.

🌱

Your Door County Garden Planner — Free

A 24-page printable planner built for Door County (Zone 5b). 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 Door County, WI. 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.