I just cut all the branches of my tree. Will it grow new branches or have I killed the tree.
Thank you for contacting the Toronto Master Gardeners.
Have no fear you did not kill your hydrangea. For the purpose of my answer I am assuming that you have a type of paniculata hydrangea producing conical shaped flowers. It could be either Limelight or Pee Gee.
We receive numerous questions regarding the proper pruning of this type of hydrangea. The following information is from two of our archived posts. If you require additional information simply type Hydrangea Pruning in the Find It Here box located to the right of the page.
“Hydrangea paniculata Limelight is one of the most beautiful, reliable and easiest to maintain of the available hydrangeas. Often it is grown in shrub form, in which case, it can be pruned down to near ground level in the spring, if desired and you will get strong new growth from the bottom which will bloom for you in the same year.
Since you have the tree form of this plant, you can subject the flowering stems from last year to being pruned right down to above 1 bud union on each stem and you can also prune down any main branch that you want to keep small. Strong new growth will appear where these cuts are made.
I highly recommend the following video available on You Tube, which shows clearly and in detail how to prune your 4-year-old tree hydrangea and should vanquish your fears of pruning your tree too much or incorrectly.”
How to Prune Tree Hydrangea 1 of 3 | Hydrangea paniculata – YouTube
https://www.youtube.com/watch?v=aLsnQVG5VNM
“The hydrangea you have, on a long trunk, is a Hydrangea paniculata which is the only species that can be pruned into a standard (think “standing”) or tree form. The flowers can become heavy with rain or snow, causing them to droop. Some people like the look of the dried flower heads on the plant over winter. If this doesn’t suit you, though, you can simply cut them off – if you simply want to tidy up the plant, cut below the base of the flower.
This type of hydrangea produces flowers on branches that are produced the same spring (known as new wood). That means you can cut the branches back in fall, winter or in early spring. I find it’s easiest to do in spring, when you can see the new buds developing. Cut each branch back to just above a set of buds, without leaving a long stump. If you want the crown of the tree to stay compact, then cut branches back closer to the main trunk (but not all the way). If you want the crown to be larger, cut off less of each branch. Except for removing clearly dead stems or crossing branches that might rub other branches or crowd the crown, you don’t really need to prune H. paniculata at all, and it will still flower.
If you want to retain the tree form, however, do not cut off all the top branches, and avoid damage to the trunk. Occasionally, you’ll get a sprout from the base or side of a tree-pruned hydrangea, too, and these should be removed.
Here’s a link to a very good website, all about hydrangeas, including pruning tips and photos. It’s called, quite fittingly, Hydrangeas hydrangeas.” Click here.