Thanks for your question. I faced a similar dilemma in 2025 when I painted my garage and lilacs were next to it. I too wanted to prune the lilacs. If you don’t mind losing some blooming in 2027, my suggestion would be to do the pruning after all your painting activities are completed. In my situation, I took the long-range view that it was better to lose a season of flowering than to do possible structural damage to my newly pruned lilacs. See the following for some information on lilac pruning:

https://extension.umn.edu/trees-and-shrubs/lilacs

https://www.growhausmn.com/blog/2024/05/21/pruning-lilacs/

Good luck. Thanks for consulting us.

The problem with my lilacs is that the mature bushes (50-60 years old) are literally up against the house. The lilacs are all in a space about 2.5 - 3 feet wide (between house and sidewalk). The younger shoots I could possibly leave alone, but I can't reach the house if I leave the mature ones. We've done maintenance pruning, but that's not going to be enough for painting.

Thanks for getting back to us.

As you consider your situation, keep in mind that lilacs are extremely resilient plants. They can take a lot of beating and still come back. Sometimes it takes a few years, but they do rebound.

It sounds to me that you will need to balance what is practical with what would be most desirable. Given how you describe things, obviously some pruning will be necessary prior to painting. In so doing, try to select the largest, and consequently the oldest, branches and remove these down to within six inches or so of the soil’s surface. In my painting project of last year, I put some ropes around the limbs that were closest to my garage and pulled them back away from the garage. At my local hardware store, I bought some corkscrew things having a ring at the top. Apparently, they are often used as a tethering post for a dog leash. I positioned these at strategic places away from my garage and with some ropes looped around my lilacs, I was able to pull most of the interfering branches away from the garage.

Bottom line, prior to painting and with selective pruning and with the possible use of ropes, get enough room between the lilacs and your house so that appropriate space is created to allow for painting access.  You really have no other choice. Despite your best intentions, some breakage will occur in your lilacs. That is unavoidable. Once the painting is done, do your pruning. Your lilacs will look a bit ragged this fall when everything is done. In 2027 there may be reduced flowering. However as the 2027 season wears on, I’m quite confident that new lilac growth will go a long way in obscuring whatever damage may have been done in 2026.

Good luck. Get back to us with any other concerns. Thanks for consulting our forum.