Purple tree collards (Brassica oleracea var. Acephala)
This perennial kale variety has been popular for many years among permaculture and forest garden folks in north America, but it is just beginning to show up in the UK.
Tree collards probably originated in the UK - they are believed to have been introduced to California during the latter half of the eighteenth century, from the island of Jersey in the English Channel where they were grown to feed cattle. You can find seeds and plants of 'Jersey kale', however, although it probably shares a common ancestor with perennial tree collards, it does not seem to be truly perennial.
This kale grows like a tall, lanky Taunton Deane; it is less robust and needs some support, especially if exposed to wind, when it gets taller. Its structure is more open than other kales, making it particularly good for under-planting with alliums and ground cover plants. It is also a very elegant plant with attractive purple leaves and stems. A mixture of this and variegated Daubenton’s at the back of a border would make a beautiful sight.
If they have good support, Purple tree collards make a good border plant. The variety needs frequent topping, otherwise it keeps growing upwards without much branching, so you can stick the cut tops in the ground close to the parent plants, and as they grow, the stems can be loosely woven together.
Propagation
The simplest way to propagate perennial kales by cuttings is by cutting fairly large branches (30-40cm), trim all the leaves off except one or two of the smallest new leaves at the tip and simply push them deep into the ground.
If you want to take cuttings and pot them up, use shorter, thinner branches (try using the small gnarly branches from nearer the base of the plant, as they are woody and often root better than new growth from the top. Spring and autumn are the best times for taking cuttings, but it is possible at any time really.
Tree collards probably originated in the UK - they are believed to have been introduced to California during the latter half of the eighteenth century, from the island of Jersey in the English Channel where they were grown to feed cattle. You can find seeds and plants of 'Jersey kale', however, although it probably shares a common ancestor with perennial tree collards, it does not seem to be truly perennial.
This kale grows like a tall, lanky Taunton Deane; it is less robust and needs some support, especially if exposed to wind, when it gets taller. Its structure is more open than other kales, making it particularly good for under-planting with alliums and ground cover plants. It is also a very elegant plant with attractive purple leaves and stems. A mixture of this and variegated Daubenton’s at the back of a border would make a beautiful sight.
If they have good support, Purple tree collards make a good border plant. The variety needs frequent topping, otherwise it keeps growing upwards without much branching, so you can stick the cut tops in the ground close to the parent plants, and as they grow, the stems can be loosely woven together.
Propagation
The simplest way to propagate perennial kales by cuttings is by cutting fairly large branches (30-40cm), trim all the leaves off except one or two of the smallest new leaves at the tip and simply push them deep into the ground.
If you want to take cuttings and pot them up, use shorter, thinner branches (try using the small gnarly branches from nearer the base of the plant, as they are woody and often root better than new growth from the top. Spring and autumn are the best times for taking cuttings, but it is possible at any time really.
