HelpfulGardener.com

I bought a house with lilacs that are more tree than bush. They are almost 20 feet tall in places and getting close to power lines.

Can I trim or prune these back lots? Can I cut them down to 3-6 feet?

I don't want to kill them, but need to cut them back.

Any suggestions?

Hi Marc and Cathy,

Congratulations on your new home! Yes, you can prune them. It's best done within 2 weeks of the finish of bloom as they set their buds for next year on this years wood (old wood), but if yours are getting too tall and potentially going to cause a problem with overhead power lines, here's how to prune to rejuvinate them.
https://www.ipm.iastate.edu/ipm/hortnews/1993/2-10-1993/lilac.html

Some basics that might come in handy.
https://spi.8m.com/care.htm
https://lilacs.freeservers.com//lilac_tips.html

Newt