Zone 4 · Fruiting Veg Growing Guide

When to Plant Eggplant / Aubergine
in Zone 4

Heat-loving crop that needs a long warm season. Start early indoors with bottom heat — slow to germinate and slow to establish. Rewards patience with beautiful glossy fruit.

Plant outdoors
May 25 – Jun 10
Start indoors
Mar 25 – Apr 10
Last Frost
~May 1
Days to harvest
70–85 days
Difficulty
Medium
Start indoors — Zone 4
Harvest window: Aug – Sep

Planting Calendar

In Zone 4, Eggplant / Aubergine should be planted outdoors May 25 – Jun 10, after the average last frost date of approximately May 1. Start seeds indoors around Mar 25 – Apr 10 for a head start.

Start 8 weeks early with bottom heat. Black plastic mulch warms soil significantly.

Care Guide

Sunlight
Full sun · 6–8 hrs/day
Watering
Regular
Spacing
18–24 inches
Soil
Rich, well-draining, warm
Days to maturity
70–85 days
Soil pH
5.8–6.5
plant tip · Zone 4

Start 8 weeks early with bottom heat. Black plastic mulch warms soil significantly.

Feeding Schedule

How often
every 2 weeks
Feed type
balanced then high potassium
Key timing
switch to high-potassium at first flower

Heavy feeder like peppers and tomatoes. Start with balanced feed, switch to high-potassium when flowers appear. Consistent feeding produces larger, more tender fruit.

Companion Planting for Eggplant / Aubergine

What you plant next to eggplant / aubergine makes a real difference — some plants actively help, others compete or attract pests.

Grows well with
  • Beans
  • Peppers
  • Tarragon
  • Marigolds
Keep away from
  • Fennel
  • Corn
  • Brassicas

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Common questions

In Zone 4, start eggplant / aubergine seeds indoors around Mar 25 – Apr 10, then transplant outdoors May 25 – Jun 10 after your last frost around May 1. Start 8 weeks early with bottom heat. Black plastic mulch warms soil significantly.
Zone 4 has an average last spring frost of approximately May 1 and a first fall frost around Oct 1. These dates vary by specific location — use your ZIP code in the plant app for precision based on the nearest NOAA weather station.
Good companion crops for eggplant / aubergine include Beans, Peppers, Tarragon, Marigolds. Avoid planting near Fennel, Corn, Brassicas, which can compete for nutrients or attract pests.
Eggplant / Aubergine typically takes 70–85 days from transplant or direct sow to harvest in Zone 4. Expected harvest window: Aug – Sep.

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Eggplant / Aubergine in other zones
Crop Guides