Two years ago I cut back a large lilac (the size of a chevy van) to a height of 4 feet. It had bloomed the previous year. For the past two growing seasons it has not bloomed. 1- is this normal? 2- Did I damage the plant forever? 3- Is there a remedy that will induce future blooms?
Some reasons lilacs do not bloom are: too much shade, they grow best in full sun; immaturity - many lilacs do not flower for five to seven years;
overly rich soil, or too much nitrogen fertilizer. Over fertilizing will promote leafy growth at the expense of flowers.
Improper pruning - pruning in summer, fall or winter pruning sacrifices flowers for next year. Prune lilacs immediately after flowering in the spring. Also, lilacs have a certain chilling requirement for best bloom. This can be a factor in warmer than normal winters. Woody plants in general do not have the habit of perfect bloom every year. Hopefully, your lilac will bloom for you next spring.