I believe this technique will work on any Viburnum, not just Burkwoodii trees.

I currently have 3 Viburnum Burkwoodii trees under development. 2 Trees are your standard informal design and the newest one is being designed in a full cascade style.

All three of these trees use my Inter-node and Leaf size reduction technique on them. My technique has been used on my 2 informal trees for about 6 years now and so I would consider it be a proven technique now.

The first step was to chop the tree back to a size where you want it to be. My first 2 trees were around 5-6 feet tall with most of the foliage out on the end of the branches. I chopped them way back with out knowing if they would back bud or not. Turns out they love to back bud! The trees budded out and Inter-nodes were exceptionally long and the leaves were exceptionally big. At this time I was pretty much a beginner was pretty much stumped at what to do next. After a couple of years of doing nothing, I got brave and started to cut back new shoots to a single pair of leaves. Our local club recommends to cut back to a pair of leaves. I decided this would not work because of the length of the Inter-nodes. So as soon as the tree produced a pair leaves in the spring, I would come along and cut the growing tip for the next pair of leaves off the branch. After experimenting with this new process, I determined you will get smaller leaves and smaller Inter-nodes if you cut the new growing tip off as soon as possible. Be sure to leave a stub to. Normally you will get 2 new buds growing out the first pair of leaves and they form a natural fork on the branch which is very desirable for ramification purposes.

The key to this technique is you have to keep on top of the tree, because Viburnums do like grow very fast. If you need a new branch let it grow as long as you want and let it fatten up. Then you can start the reduction technique when needed.

Here are photo’s showing the technique on a couple of Viburnum Burkwoodii trees. This technique has been used on the trees for about 6 years now. The trees were originally chopped in the summer of 2009.

Here is a shot of a normal leaf (They can be larger) and a leaf that has been through the reduction technique. So the goal is get all of the leaves down to the smaller leaf size. Also shown is a typical shoot that is cut off after the first pair of leaves are produced. Notice the shoot leaves are slightly bigger then the first leaf.

Here is shot of a typical Inter-node length on a growing branch, they are very long and the leaves are very big. On the left in the photo you can see leaves that have gone through the technique and they are much smaller then these untouched leaves.

Here is a photo of my largest tree before applying the reduction technique. This tree had already gone through one reduction technique earlier this spring. This will be its second training round this year. The lower branch on the left has been allowed to grow unchecked to increase its size.

Here is a close up shot of typical ramification on this tree and it also shows numerous new growing tips that are going to be removed and leave a small stem. If you miss a trimming session on these tips you can still cut them back to a single pair of leaves. The quicker you cut these tips off the smaller the first pair of leaves will be. The Inter-nodes will also be very short. Timing is critical to get smaller leaves and Inter-nodes. This techniques does not hurt the tree either. I have spent 6 years working on this technique and as you can see the tree is very healthy. This techniques will also prevent the tree from flowering next year depending on how late in the season you performed the last trimming.

Here is a closeup of the growing branch where the 2 tips in the middle of the photo are going to be cut off.

Here is a closeup of the same branch after the 2 tips are removed. The rest of the growing tips on the tree will be removed unless I am trying to grow out a branch.

Here is a photo of the tree after all of the growing tips have been removed.

 

Here is a comparison before the reduction technique was applied and after it was completed. This technique will  have to be repeated through out the growing season.