Zone 4 · Herbs Growing Guide

When to Plant Basil
in Zone 4

The quintessential summer herb. Plant near tomatoes — they're culinary and companion garden partners. Pinch flowers immediately to keep leaves producing.

Plant outdoors
May 25 – Jun 10
Start indoors
Apr 25 – May 5
Last Frost
~May 1
Days to harvest
25–35 days
Difficulty
Easy
Wrong season — Zone 4
Harvest window: Jul – Sep

Planting Calendar

In Zone 4, Basil should be planted outdoors May 25 – Jun 10, after the average last frost date of approximately May 1. Start seeds indoors around Apr 25 – May 5 for a head start.

Wait for warm nights before transplanting. Basil blackens below 50°F.

Care Guide

Sunlight
Full sun · 6–8 hrs/day
Watering
Regular
Spacing
12–18 inches
Soil
Rich, well-draining, moist
Days to maturity
25–35 days
Soil pH
6.0–7.0
plant tip · Zone 4

Wait for warm nights before transplanting. Basil blackens below 50°F.

Feeding Schedule

How often
every 3 weeks
Feed type
balanced (10-10-10)
Key timing
throughout growing season

Moderate feeder. Liquid balanced feed every 3 weeks keeps growth lush. Pinch out flowers to maintain leaf production.

Succession Planting

Sow every 3 weeks

Sow every 3 weeks from last frost through midsummer. Basil bolts quickly in heat — having a fresh young plant coming along as the old one flowers keeps you in leaves all summer.

Companion Planting for Basil

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

Grows well with
  • Tomatoes
  • Peppers
  • Oregano
  • Chamomile
Keep away from
  • Sage
  • Fennel
  • Thyme

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Common questions

In Zone 4, start basil seeds indoors around Apr 25 – May 5, then transplant outdoors May 25 – Jun 10 after your last frost around May 1. Wait for warm nights before transplanting. Basil blackens below 50°F.
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 basil include Tomatoes, Peppers, Oregano, Chamomile. Avoid planting near Sage, Fennel, Thyme, which can compete for nutrients or attract pests.
Basil typically takes 25–35 days from transplant or direct sow to harvest in Zone 4. Expected harvest window: Jul – Sep.

Recipes using this crop

Great ways to use your harvest — see all recipes

Preserves & Condiments

Classic Basil Pesto

10 min · easy

Preserves & Condiments

Bright Basil Oil

12 min · easy

Free app · iOS February 2028

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Basil in other zones
Crop Guides