Tree Collards Are A Super Food Waiting to Be Discovered


One of the primary missions of Dr. Cowan’s Garden is to introduce wild, perennial and other unusual vegetables into the American diet because these vegetables tend to be more nutrient dense than common garden vegetables and richer in disease-fighting phytonutrients.  Our modern vegetables have been bred to be shipped long distances, to be stored, and to have a higher sugar content to “improve” flavor.  None of these parameters are beneficial for health.  What we really want from our vegetables — in addition to flavor — is the concentrated disease-fighting substances that all plants make to help them survive.


Tree collards are one such example of a super food, a perennial vegetable waiting to be discovered.  We all have heard about the robust disease-fighting abilities of the brassicas family of vegetables.  Cabbage, collards, Brussels sprouts, etc., all concentrate the sulfur-rich chemicals that turn out to be so important in helping to prevent such diseases as cataracts, heart disease and cancer.


Tree collards are essentially collard greens that have “forgotten” how to go to seed.  Native to Africa, they continue to grow for up to 15 years.  They are an exceptionally hardy plant, easily withstanding temperatures as low as -15 degrees F.  As the years go on, they become a woody, gangly shrub, easily reaching heights of 10 to 12 feet.  At the ends of their numerous branches are clusters of dark green leaves with a purple tinge. The purple color means it is particularly good at making those sulfur-rich compounds.


Tree collards are resistant to most of the usual diseases and pests that tend to plague the other brassicas members, even shrugging off all but the most intense invasion of aphids.  Tree collards are also one of the plants richest in calcium, something the gardener quickly discovers because the only care they require is the yearly application of a handful of calcium-rich bone meal.  That and pruning to keep them from getting too heavy with leaves make them one of the easiest plants to grow and why they are the “star” of the permaculture movement.


All of the tree collards in our Napa Garden - Tree Collard Powder was grown by me in our Napa garden.  Our 50-or-so plants are now about three years old and have become big, gangly bushes.  The leaves have a cabbage/Brussels sprout-type of taste and pair well with any dish for which you would otherwise use kale or some other green.  Like ashitaba, Tree Collards are another super food that has yet to be widely discovered.  We are glad to be the first company I know of to offer Tree Collards in any form to our beloved customers. 


In health,

Tom Cowan, M.D.


  • Customer Support

    Hello Breanne,

    Thank you for the comment. You can find Ashitaba on our website (powdered). As far as live Ashitaba plants, we currently are not offering them on our website.

    Customer Support

  • breanne

    I love the info!! 💕 I would also be interested in growing things like this where can we access this, ashitaba also! thanks!

  • Deb

    Would like to grow our own Collard Tree. How can we get started?

  • Customer Support

    Hello Robert,

    These are not the same greens as are in our Low-Oxalate Greens powder. At this time, we no longer offer the Tree Collards.

    The greens in our Low-Oxalate Greens are: lacinato (dino) kale, mustard greens and collard greens.

    Customer Support

  • Robert Mitchell

    Q: Are the collards in your Low Oxalate Leafy greens Tree Collards I eat organic collard greens but I do not think they are your African Tree Collards. Just trying to consume all these superfood veggie you are talking about.

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