Thanks for your question.

This looks like a panicle hydrangea (Hydrangea paniculata). Although I can’t tell for sure, it might be the variety known as “Limelight”. If I am correct, it blooms on new wood which means that now (early April 2026) is the opportune time to prune it.

Here are my general pruning suggestions:

1). Your first step should be to remove all dead, damaged, and crossing stems. The dead stems will have a thin, gray appearance. They are probably brittle and should snap off. If there are large branches rubbing against each other, prune to eliminate this rubbing. Very low and sprawling stems near the ground could also be removed. Cut all the way back to the base (soil line or main trunk).

2). The dense tangle in the lower middle of the plant should be heavily thinned. Remove at least 1/3–1/2 of these stems at the base. Initially start by removing the thinnest stems.

3). On a more general note, you should reduce the height of the shrub and shape it to create a vase shape so that the base of the plant gets more light exposure and air circulation. This hydrangea responds well to cutting back by 1/3 to even 1/2. In doing this, make cuts just above a pair of buds. Cut the taller stems down so that there are about two feet in height. Focus on the taller stems that are now growing in front of the lower half of the window.

4). If you want, snip off the old flower heads. This is not absolutely necessary, but it would create an overall “neater” appearance.

5). Periodically while pruning, step back and look at things. Your goal is to have a total of 6 to 10 main stems.

See the following for further information on these and related points:

https://extension.umn.edu/trees-and-shrubs/pruning-hydrangeas

https://extension.umn.edu/planting-and-growing-guides/pruning-hydrangeas-best-bloom

https://www.youtube.com/watch?v=TugeQTuA5MI

https://www.youtube.com/watch?v=rOUSBTraQEo

https://extension.unh.edu/sites/default/files/migrated_unmanaged_files/Resource008054_Rep11755.pdf

Good luck. Please get back to us with any additional questions. Thanks for using our forum.