Planting your Tree Collards
Tree collards, like most vegetables, prefer a soil with with a fair amount of organic matter and a pH around 6.5. However, they can tolerate a range of soil types and growing conditions. They prefer regular watering during dry months, but, once established, can survive periods of drought. They will not be as productive during dry months, but they will slow their growth and survive a surprisingly long time. In a hot desert climate you may want to plant your collards under the canopy of a deciduous tree that casts filtered shade. In our mild climate they are planted in full sun and thrive.
Tree collards can reach over eight feet in height in fertile soil with regular water and proper staking. They can also be kept to four feet with judicious pruning. You can use tree collards to screen out an unsightly view of the neighbors or create a privacy screen. If you don’t have a garden bed or want to keep your tree collards portable you can plant your tree collards in a large pot (something like a wine barrel would be ideal for one plant- though this would be very heavy).
Tree collards can tolerate temperatures in the low twenties and actually taste best after cold spells. Our collards have never gotten below 23° F so we don’t know for certain what their exact lower limit is. We have read that they will get killed somewhere in the teens (-7° C). One solution for borderline areas is to plant them in pots and move them into a shed during very cold nights. You could also take cuttings right before the coldest time of year and root them in a sunny window, then plant your new plants outdoors when the weather warms. We are going to experiment to see how long cuttings can remain viable in the fridge.
Here in the Bay Area we rarely notice any diseases or pests other than powdery mildew during the heat of the summer. Deer love tree collards so you’ll want to plant them somewhere protected.
The actual process of planting your collards is very simple. You’ll likely want to incorporate some well aged compost or manure to your planting area and loosen the soil with a garden fork or spade. Space your tree collards two and a half to three feet on center.
Here is a video we did on planting a tree collard.