We recently received a question from a customer about growing tree wisteria. The customer watched our video on how to train the popular Wisteria vine to grow in a beautiful tree form. Felix Cooper, our director of research and development, answered his questions.
Customer Question: I would like to find out about the first steps from the first year and how to prune it, when to prune it, and when/how to pinch out the growth tip. Do I need to do this every year? How can I care for a second or third year specimen?
– Norm
Felix Answer:
Hi Norm –
I’ll try to describe the process of caring for the wisteria tree in its early stages. The key is to recognize that it takes about 5 years for the “trunk portion” to become woody and sizable enough to support a top.
Starting out, you’ll need some kind of stake right next to the wisteria plant to serve a support for the young vine. T or U posts work well, as does a metal conduit driven deep enough to not topple under the weight of the top (typically 2-3’deep). After that, the growing process will look like this.
1. Your vine should produce a primary shoot which you should tie to the stake, keeping the vine as straight as possible.
2. Any branches along the length of the shoot that might emerge should be carefully cut off to stop their further development and direct the primary energy of the vine toward reaching the length of trunk you desire. I’ve seen these trained at 2’ and all the way up to 8’ tall. This is up to your preference. Keep in mind that you will be the one shaping the canopy each year, so don’t make it so high that you won’t be able to manage the top with some hedge shears.
3. Once the primary vine has reached the height that you want branching to begin, you should pinch out the growth tip about 4-6” above this point. This should induce branching in the area below where you pinch back the vine. Note: you will also get some shoots to emerge at various points below this region along your newly established trunk. Anything along the trunk should be cut off (if you get them early you can just pluck them off without causing any damage). Leave the top branches to develop.
4. The second year, you can trim back the prior year’s branches to a length you like before the plants break dormancy. Again, you will need to manage suckers and shoots that emerge along the trunk and from the soil line. Encourage growth at the top of your trunk and tip the shoots when they start to lay over (i.e., they’ll no longer support themselves in the vertical position).
5. Repeat this care each year and start shaping up the “head” of the tree to the size you like.
Check out the original video here!