If it has stopped blooming altogether, I would give it a good pruning and next year it should come back. One of the things you need to do with a lilac is cut off the spent blooms at the end of the blooming season. Unlike some other flowering shrubs, it does not benefit from having old wood left.Sara said:I have two lilac bushes near my house that I planted 6 years ago. They had blossoms on them when I planted them and they bloomed the following year, but they've never bloomed since. Anyone know why and what I can do to make them bloom again?