Knowledgebase

how and when to prune a smokebush to become tree-shaped #885576

Asked September 17, 2024, 1:19 PM EDT

The attached image is of a smokebush which volunteered in my flowerbed this spring. All of its growth has occurred this spring/summer, from a tiny seedling to the tallest limb being 4 feet tall. I intend to transplant it to the center of the bed, about 3 feet away. It will have the same soil and amount of sunlight. I would like to train the bush to grow as a small tree. Do you have recomendations on how to prune the smokebush to become tree-shaped? I plan to transplant it by Oct 20, which is as late as I can because we are leaving and will not return until early June. Should I prune the bush before I go, or wait until I return in June? Or is it better to wait for a year when I can trim it after a freeze and before it buds? Thanks for your help- S Robinaugh

Kent County Michigan

Expert Response

Transplanting it in October is a good idea. However, you may want to move it before the 20th so that you can water it repeatedly before you leave. 

When you transplant it, I would remove all the limbs except the one you think will be the best trunk for your tree. Select the strongest, most upright branch. Remove the rest. I would stake the limb that you want to be the trunk. 

Here is a link that explains how to plant a tree:

https://www.treesaregood.org/Portals/0/TreesAreGood_New%20Tree%20Planting_0621.pdf

Key points from that link: Make sure you do not plant it too deeply. See how they stake the tree in the drawing. You want to do something similar, on a much smaller scale, to encourage the branch you select to become the "leader" and grow into a trunk. 

Next spring, your smoke bush is going to put out a lot of growth. You need to let some of the side branches grow the first season. The branches are important because the leaves are providing nutrients to the tree and helping it grow stronger. If you remove all the lower branches, it may put out a bunch of growth higher up and become too top heavy and start to bend. You will have to gauge how strong the main trunk is before you start removing the limbs that want to grow outwards and low on the trunk. (If a side branch starts to compete with the leader--it's growing very tall and upright--you can cut it back.)

Here is a link to explain pruning of young trees:

https://www.treesaregood.org/Portals/0/TreesAreGood_Pruning%20Young%20Trees_0621.pdf
This should get you started. Feel free to write back next season if you need more guidance. 

Lindsey K. Kerr, MS, MHP (she, her, hers) Replied September 17, 2024, 4:09 PM EDT

Loading ...