lilac trees

My parents have had lilacs for years and they say this just happens - one year the flowers are great and foliage a bit bare, the following year it is the opposite. So it is maybe not something to worry about, but I am sure someone else will know if there is a way of moderating this so you get a consistent show each year.

Do you cut your lilac bushes at the wrong time of year as it is a tip bloomer. If you cut it cut after it has bloomed about now (June then the new foliage should produce blossom next year. Try giving it some feed in the autumn. Lindak.

Is your soil acidic?

Thanks so much everyone for your help.