Purple Tree Collards: a perennial grown from cuttings

Purple Tree Collards are a type of collard (Brassica oleracea, var. acephala) that is perennial wherever the ground doesn't freeze solid in the winter (typically zones 8-10, though some people grow them in colder zones with winter protection. They are prized for their tender texture, mild sweet flavor, and especially for their year-round production. This year-round leaf production is due not so much to their cold-hardiness (many kales are hardier) but to their inability to flower and make seed. 

Most leafy greens produce leaves in their vegetative phase, then move on to the flowering phase. In flowering phase, they stop making new leaves, stretch out, and make large branching stalks of flowers. The flowers turn to seed pods, which take a couple ofmonths to ripen fully before the seed is mature--at which time the plant usually dies. Some perennial collards don't die after making seed. But even if the plant survives, it doesn't provide a usable harvest of leaves during the flowering/ripening parts of the cycle--which is almost half the year. The big advantage of tree collards as a food plant is not only that they don't die, but that they don't bolt to flower, or spend months ripening seed, staying perpetually in the vegetative, leaf-producing state. It is thought that Purple Tree Collards are a natural hybrid that's unable to make seed because of genetic incompatibility. Whatever the reason, the outcome is a beloved heirloom that has been passed down by cuttings for over a century.

There are several strains of perennial kales and collards in the Channel Islands of Britain, where there are wild cabbages/kales/collards that can cross with cultivated ones, and the foggy, moist climate is ideal for their survival. Most of them have a strong flavor and are mostly fed to livestock.

Collards bred for delicious human food have been an important part of African cuisine and culture for centuries, and were carried worldwide by the African diaspora. (Many annual varieties have been preserved and saved by individual gardeners and their families. For more on these, see the Collard Ultracross listing.) Purple Tree Collards, with their perennial habit and mild flavor, have been preserved and passed down from neighbor to neighbor in African-American communities for a very long time, unknown to mainstream agriculture. We are grateful to all the anonymous gardeners who saved this treasure for the world to enjoy. 

How to Root Tree Collard Cuttings

When your tree collards cuttings arrive, put them in the refrigerator in the paper and plastic wrapping they came with. Or, if you have unwrapped them, they can stand in a glass of water overnight. Don't leave them in water more than a day or they will start to rot, and don't leave them in a hot place. If you can't pot them up within a day, put them between layers of damp paper in the fridge.
 
It is easiest if you root them in a pot rather than the ground, unless your situation is such that you just can't take care of a pot.
Use a gallon pot or something approximately that size. You want a pot at least 6" across, and at least 8" deep so they don't dry out too easily. Fill your pots with good potting mix, well-moistened but not soggy. Just pile the soil in so that it is fairly loose, not hard-packed. (If you need to put them straight into the ground, prepare a bed with lots of compost, a fine, fluffy texture, and no weeds.)
 
Now, make sure you know which is the top of your cuttings and which is the bottom. You cannot rely on the diameter--sometimes they are thicker at the top! They will have been shipped with the bottom in moist paper. If they have been unwrapped and both ends are cut, look at the bud scars on the stem, the browned areas where a leaf was attached. When the cutting is right-side-up, the scars are somewhat heart-shaped. The tiny bud that will make the new leaf sits in the notch on top of the heart.
 
Stick each cutting into the potting mix.  Give each cutting its own pot. Use a pencil or similar tool to make a hole slightly smaller than your cutting, to help ease it into the soil. The soil should come halfway up the cutting or more. I like to stick them in at a slight angle rather than absolutely vertical (I think it helps rooting somewhat) but that's just me. Top up the pot with soil so that it comes within 1/2” of the top. Once the cutting is 1/2 to 2/3 buried in the soil, firm the soil around it.
 
Keep your pots in a place with bright shade. They should not be in the dark, but they shouldn't have baking sun. A north or east window is often good, or a porch or under trees in dappled shade. If you live where it is cool and overcast, they will not need as much shade. In a hot, bright, dry climate, they need protection. Choose a place where you would be comfortable sitting for several hours. Create shade if needed.

Leaves will appear quite soon--that does not mean the cuttings are rooted yet. (Think of flowers in a vase; buds can open while the cut stem is in water.) As leaves and stems appear, take a look at them. Do they look pale and elongated? Then they need more light. Leaves should be green with possibly some purple. Stems should be sturdy. Adjust the location to give them enough light without killing heat. At this point, a growlight indoors is often the easiest and best alternative. You want a lot of light without a lot of heat or wind. Room temperature is great.

Like any transplant, the Collards are ready to go into the garden when you can see a root trying to come out the hole in the bottom of the pot. This can take anywhere from 2 to 6 months, depending on temperature and light conditions. After six months, if you haven't seen any roots, you could gently slide the damp soil out of the pot. But if you decide on this strategy, have your planting hole ready before you start. If there are no roots, you'll need to put it back into the pot. If there are, you should slide it into the planting hole without further disturbance.