Lilac Bush

Question

My Mother always told me to trim/prune the ‘done’ blooms from the bush so it does not go to seed.
Is this correct? Or should I just let it go (grow?)

Answer 1

That is correct. Deadheading the blooms after they flower prevents the seeds. Once they reach about 6 feet it is also important to prune:

https://www.gardeningknowhow.com/ornamental/shrubs/lilac/pruning-lilac-bushes-when-to-trim-lilac-bushes.htm