Collard Greens

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Brassica oleracea





Quick Reference

Optimum Soil Temperature 15-22°
Days to Germination 7-10
Days to Harvest 80 days from transplant
Direct Sow or Transplant Transplant
Distance Apart 60cm
Soil pH 6.0-6.5
Annual/Biannual/Perennial  Biannual but grown as an Annual


Native to Asia Minor (Turkey) and the Mediterranean.  Collard Greens are one of the oldest members of the cabbage family.  Were cultivated by the Greeks and Romans over 2000 years ago.

Originally Collard was named Colewort (wild cabbage).  It is also known as Nonheading cabbage, or Tree Cabbage


Grow well in warm weather but can withstand cold, in fact the flavour is enhanced by light frost.

Start seedlings out in trays and transplant out when the plants have four true leaves

Keep soil moist, but not too wet and mulch well.  Seedlings will bolt if they dry out in early stages.

Storing harvested Collards:Store well in a root cellar situation, or in the fridge for 2 weeks.  Can be frozen (good flavour) or dried (fair flavour), does not can well.

Seed Saving:  Insect pollinated.  Will cross pollinate with all other brassicas.  Requires 1km exclusion from other plants.  40 plants required for genetic diversity.

Seed Life:  Five years


Collards are heavy feeders.  Fertilise three weeks after transplant.Remove any outer dead leaves

Fun Facts

Rich in Vitamin K and Calcium, high in fibre, β-carotine ,Vitamin A, and folate

Lowers cholesterol, anti-cancer properties

100 grams of Collard greens contains 30 calories

State vegetable of South Carolina  where each year the Ayden Collard Festival is held.  The festival boasts a parade and a collard eating contest.

Mess o’greens is a popular dish in the Southern US made from collards and ham hock (it’s basically a boil up)

Can be put into dips, smoothies and soups.  Is excellent in a boil up.


Downy Mildew – pale spots or blotches on leaves. Possible mildew on underside of the leaves.  Space plants to allow for good air circulation.  Weed.Potassium Deficiency – scorching or burning on leaf margins.  Poor quality hearts.

Magnesium Deficiency – yellowing between veins on older leaves.  Add fertiliser.

Molybdenum Deficiency – leaves thin and strap-like, poor growth.  Add fertiliser.

Boron Deficiency – hollow stems.  Add fertiliser

Cabbage Ring Spot – circular infections on the lower outer leaves.  Leaf drop.  Remove and destroy infected plants.  Crop rotation.

Heartless Cabbage – Soil too loose.  Drought.  Not enough compost

Split-headed Cabbage – Rain after a dry period.  Heavy frost.  Use frost cloth.  Water regularly.

Bolting/Running to seed prematurely – cold weather followed by hot weather.  Root exposure

Club Root – plants stunted, deformed roots.  Add lime to soil.  Destroy diseased plants.  Ensure good drainage.  Crop rotation.


White Butterfly/Diamond Backed Moth – holes in vegetation in late spring, summer, autumn.  Protect young plants with insect meshAphids – small insects clustered in developing heart or crown.  Keep plants well watered in dry weather

Slugs and snails – holes in leaves or stems in winter.  Digital removal (pick the bugs off), coffee grounds, ground egg shells said to be a deterrent.

Whitefly – underside of leaves covered with tiny white insects that will fly when disturbed.

Cover your garden with insect netting to avoid having your plants become a meal for caterpillars and bugs.  There are a variety of sprays and solutions (both organic and non-organic) such as Derris Dust or Quash available to combat such pests.