Zone 6 · Leafy Greens Growing Guide

When to Plant Collard Greens
in Zone 6

The most heat-tolerant and cold-hardy of all the brassica greens. Harvest outer leaves all season. Flavour improves dramatically after frost. A Southern US staple.

Plant outdoors
Mar 20 – Sep 1
Start indoors
Feb 15 – Mar 5
Last Frost
~Apr 1
Days to harvest
60–80 days
Difficulty
Easy
Growing — Zone 6
Harvest window: Apr – Feb

Planting Calendar

In Zone 6, Collard Greens should be planted outdoors Mar 20 – Sep 1, after the average last frost date of approximately Apr 1. Start seeds indoors around Feb 15 – Mar 5 for a head start.

Near year-round with mild winters. Fall collards can overwinter and produce into February.

Care Guide

Sunlight
Full sun to partial shade · 4–8 hrs/day
Watering
Regular
Spacing
18–24 inches
Soil
Fertile, well-draining
Days to maturity
60–80 days
Soil pH
6.0–7.5
plant tip · Zone 6

Near year-round with mild winters. Fall collards can overwinter and produce into February.

Feeding Schedule

How often
monthly
Feed type
high nitrogen
Key timing
throughout growing season

Heavy feeder. Nitrogen produces large, tender leaves. Feed monthly throughout the season.

Succession Planting

Sow every 4 weeks

Sow every 4 weeks from spring through midsummer. More heat-tolerant than most brassicas, making succession easier in warmer zones.

Companion Planting for Collard Greens

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

Grows well with
  • Beans
  • Onions
  • Beets
  • Celery
Keep away from
  • Tomatoes
  • Strawberries
  • Fennel

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Common questions

In Zone 6, start collard greens seeds indoors around Feb 15 – Mar 5, then transplant outdoors Mar 20 – Sep 1 after your last frost around Apr 1. Near year-round with mild winters. Fall collards can overwinter and produce into February.
Zone 6 has an average last spring frost of approximately Apr 1 and a first fall frost around Oct 31. 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 collard greens include Beans, Onions, Beets, Celery. Avoid planting near Tomatoes, Strawberries, Fennel, which can compete for nutrients or attract pests.
Collard Greens typically takes 60–80 days from transplant or direct sow to harvest in Zone 6. Expected harvest window: Apr – Feb.

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Collard Greens in other zones
Crop Guides