Everything you never knew you wanted to know about Tree Collards

Welcome to the Perennial Tree Collard Blog.  I'm currently compiling my 20 years or so of growing Tree Collards and hope to have all aspects of it's propagation, cultivation and food preparation up soon.

For now, I will just post what I've already posted on numerous Garden Forums around the Web until I find the time to elucidate and edit at length.

"A rose by any other name . . ."

"I've been called Tree Collard, Tree Kale, Walking Stick Kale and Purple Tree Collard.  Call me what you will, but make sure to grow me for at least a year, make some cuttings and pass me on as I do not grow true from seed and I RARELY go to seed.

My leaves only turn purple in cold weather!!  I'm in the Brassica family & look more like a collard than a kale. Whatever you choose to call me, culinary-wise, I can't be beat."

This California Hybrid can withstand even light snow (Oregon) as well as temps in the 90s & 100 (here in Walnut Creek, CA).

Brassica oleracea var. acephala

These perennial veggies are great for the backyard organic vegetable gardener or mini farm as they never stop producing. High in Calcium!!  Sweeter and Tastier than regular collards (especially during the Fall, Winter, Spring when the whether is cooler and the leaves turn purple). And it's one of the favorite foods for our chickens.  Here are some of the locations where the TCs are thriving that I've shipped to: Florida, Texas, North Carolina, Louisiana, Southern California, Oregon, Washington and of course California.

If you and/or your family, friends, neighbors eat lots of greens, it's worth it to have at least three tree collards growing for abundant, continuous harvests.  Once you have some mature plants, please do your part in making new plants and passing them on.

I've grown plants up to 11' tall and 3' wide & recently heard of them getting to 18' plus next to and attached to a wall.  PLEASE REMEMBER - The trunk and branches get woody after about three years, so if you want to share cuttings, you must start to make new cuttings between 18 months to 2 years when the top branches are still tender and green (not woody).  Also, as the plant matures and gets woody, the leaves get smaller on the many side branches.  The main trunk will continue to have very large leaves until you have to prune it at ten or more feet.  Pruning the main trunk is dependent on whether you have it growing next to a very tall wall or whether like most growers, you have it tied to a ten foot tree pole.  Even with two feet of that pole in the ground, there are times that the upper 8' will not support a very large and very top heavy three-year old tree when the ground gets soaked and/or the wind gets really strong.  More about this later when I create a detailed post about cultivation and propagation.

A Morsel of History and Culture

Some people call them Tree Kale or Walking Stick Kale or Tree Cabbage. If you've heard of Walking Stick Kale, this isn't it. In the UK, people tend to refer to what everybody else in the world calls Collards as Kale.  This is very confusing.  Kale is Brassica napa. Regular Collards are Brassica oleifera var acephala. Collards are a non-heading cabbage. Kale is a more salady vegetable, often used as a winter salad green that is available over a longer season than lettuce. Although they are considered different species, there are no genetic barriers to crossing them. Kale is commonly eaten on the European continent, especially as you go further east where lettuce is harder to grow due to the severity of the climate. It is not commonly eaten among the British, which is why they might use the word for something else. If you ever travel in Europe and get something that looks like salad greens but is a bit tougher and heartier than lettuce, and often fairly pretty shades of blue-green or purple, often with a ruffled leaf margin (varies from highly frilled to just a bit), that's Kale

Collards are very commonly eaten in the subtropics and tropical highlands, because they don't bolt as easily as their domesticated cousin, cabbage. I don't know why...they might actually have a bit of tropical blood in them. You can grow them in places like southern Georgia where it is too hot for cabbage. For this reason, Africans and Afroamericans often eat Collards while northern and eastern Europeans and their descendants far more familiar with cabbage. Cabbage was bred from wild cabbage (which I have seed for) to have the fat tight bud, so as to be storable through the winter. It was bred from probably a more northerly strain of the same species that Collards were bred from.

The Tree Collards I have are probably of the famous strain that passes from neighbor to neighbor and at certain permaculture plant sale circles in the East Bay Area. They have decidedly purplish leaves in Late Fall & Winter with a slightly ruffled margin. Plus that might explain why the California strain is reputedly more tender and palatable than other Tree Collard strains, which are reputedly tough and cabbagy. I've been growing them in a hot Summer climate for 10 years and they have adapted well to the heat. They were bred as livestock fodder originally. Since there is some confusion regarding Kale versus Collards, plus no barriers to hybridization, that might explain how someone might have hybridized them and not realized that there is a difference.


Additional Insights~

As a perennial form of cabbage, it is said (I have not seen or actually talked to someone who has grown them this long) to live up to 20 years or more although you might need a scaffold to grow them up. They will get woody after about three years AND the leaves will get smaller, BUT they'll keep growing. And you can espalier them as well.

This species includes some of our most common vegetables such as the cabbage, cauliflower and Brussels sprouts. Although not widely known, these perennials can be amongst the most productive food plants that can be grown in the garden. They grow best in a sunny position and succeed in most soils, doing well in heavy clays. However, they can also be grown in partial shade  They do not like very acid conditions. Prune heavily to get multiple brances and more harvest.

The true wild form of B. oleracea is the WILD CABBAGE, which can still be found growing by the sea in many parts of the country. ( I GROW THEM & have seeds). A short-lived evergreen perennial, it can grow up to 1.2 meters tall. The leaves have a similar flavor to cabbage and collard leaves.  Plants will usually live for 3 - 5 years, though some have been grown for 10 years or more. they do, however, become rather straggly as they age. Whilst most of the plants developed from the wild cabbage have lost the ability to be perennial, there are just a few forms where the perennial tendency has been increased.

Propagation of Cuttings

This post has been a long time in coming.  Sorry for the delay.

As stated in the other post, make sure you are taking cuttings from green branches and not woody branches.  Woody branches will root, but will be stunted.  Please read that post.

Always make sure to put at least an 10' tree pole next to the plant once you've planted it in the ground.  These plants get very top heavy.  I've had 12' plants that were tied to tree poles fall over in strong winds when the ground gets really wet during the Winter.  Ideally, the tree pole will have three feet in the ground.  This only matters if you'd like to grow the collards upwards of 10'.  If you continue to prune the main trunk AND the side branches, you can keep it smaller.

(Please aid the plants survival and propagation by sharing cuttings with other gardeners.  You can send them here for directions to rooting or better yet, root them first.)

Side note:  Unless you are taking cuttings to make new plants, you'll always be harvesting just the leaves.

I have grown plants in two formats.

1)  I let the plant grow to about four feet plus and then top two feet off and root that cutting.  Once the apical meristem is removed (the top of the plant) the plant will immediately direct its energy to the lateral meristems (lateral branches).  These branches can will then provide you with more opportunities to make cuttings.  I will cut all the lateral branches when they get about 4'.  The plant will now start to get up to 4' in diameter.  You can repeat this process at least one more time. Growing in this manner, the leaves will be smaller than in growing them in Format 2, however, you will have a lot more production.

2)  I let the plant continue to grow without topping it.  Somewhere around 6' tall, the plant will start putting out lateral branches.  You can eventually make new cuttings from these branches.  I prefer this method because I love seeing a 10' plus high plant with GIANT leaves.  However, (as you can see by the two photos attached), this three year old plant with one stock has just had all of it's lateral branches pruned.  You can see the woodiness to the branches.  These branches will produce quite small leaves and you won't be able to make new cuttings because of the woodiness.

Rooting the Cuttings

Make a cutting with at least 5-6 leaf nodes.  Strip all leaves off the cutting except the top smallest leaves.  I dip the end of the cutting in a rooting hormone, although this isn't necessary.  My neighbor has just stuck them in the ground (in Spring and Summer) and some root and some don't
The medium I use is 50% perlite and 50% vermiculite.  I use a 4" pot.  I then cover the pot with a plastic bag to make a mini greenhouse and keep it in total shade (Summer) or indirect light for the next two months.

They take a really, really long time to root!
This is why you can't find them at nurseries; there's no profit margin given the amount of time and energy it takes to make new plants.

(It's possible that your cuttings will flower in the first three months if the weather is warm - like late Spring or into Summer.  Unfortunately, you'll have to start over.  I think it has something to do with them being in the pot - possibly a bit root-bound -)

Be very careful when removing the plant from the 4" pot as the roots are very delicate and they are growing at the very end of the stem cutting.  These roots can fall off easily if you're not careful.  I like to let the soil dry out completely before popping it out of the ground.  I have often transplanted them up to one gallon pots before putting them in the ground.

Give them a good feeding of Calcium every month or two.

Here is an example of a cutting being rooted in a 50/50 vermiculite/pearlite mixture.  Cut a metal hanger and positioned on the pot to allow for a plastic bag to enclose it in order to create a humid environment.  I will often put three or four cuttings per pot to reduce the number of pots.  After about 4-6 weeks, I put them out of the medium to check for roots.  REMEMBER~~ The roots that form are VERY delicate and fragile.  They only grow at the very bottom of the cutting and can fall off easily if you aren't tender when checking on them.  Ideally, you put one cutting per pot and wait until you see some growth and/or you see roots coming out from the bottom of the pot.

Woody Cuttings Propagated that are Stunted!

The most important aspect to making new plants is to make sure you take cuttings prior to your Mother plant getting too woody.  It is highly recommended that you start to make new plants for yourself (or for others) between Year One and Year Two.  If you don't, you will eventually end up with a mature tree collard that you can no longer make cuttings from.  Timing of cuttings depends on your Zone and your micro climate (full sun, partial shade, mostly shade).  My three year old plants growing in full sun in Zone 9 are now too woody to make new cuttings.  "Too woody" means that even when I cut the first 4 - 6 inches of a top branch, the woodiness has crept too close to the apical meristem (tip of the branch).  I will publish more photos soon of cuttings that aren't woody.

Close-up of new branches forming on Woody trunk

6 month old cutting.  Notice how it's stunted due to the cutting being taken from a woody branch.