When trimming lilac bushes, it's best to prune them back to about one-third of their height, but you can cut them as close as 12 to 18 inches from the ground if necessary, especially for rejuvenation. This encourages healthy growth and blooming in the following season. However, avoid heavy pruning in late summer or fall, as this can remove buds for the next year's flowers. Always ensure to use clean, sharp tools for a clean cut.
Do not trim a lilac bush in the spring because you will cut off all of the flower buds. Trim a lilac bush after it flowers.
Yes, you should trim bushes
Leafminers
Yes they do, in the winter.
Are lilac bushes acid loving plants OR DO THEY NEED ALKALINE FERTILIZER
It is not advisable to trim bushes in frosty weather.
Lilac bushes have been around for a long time. It was growing in southeastern Europe before Christ's time.
it is an idiom
I just read on Fox Hills Lilac Farm's website that the best time is between April and Oct. They stated that 75% are done in the fall.
I've never had any issues with it, and Lilac is used in soaps, for traditional intruments and tablewares, and is even candied and used in tea and some country wines in the Balkans where it is native. I burned a whole 10' bush that had become diseased this past winter.
Lilac bushes are not listed on the Cornell University's list of poisonous plants. The University of Arkansas information booklet on poisonous plants has listed Lilac as nonpoisonous with edible flowers (can be used for food). CAUTION: Now don't get lilac bushes confused with the Persian Lilac (aka Chinaberry Tree) which is NOT related to true lilacs at all. The ASPCA Animal Poison Control Center list the Persian Lilac tree as poisonous to dogs and horses.
Lilac bushes can be pruned in the late winter if the bush is overgrown. However, lilacs should be lightly pruned in early spring after they have finished blooming.