Has anyone else got a problem with their lilacs? I have 2 white lilacs which, for the 6 years we've been here, have flowered beautifully and heavily. Both trees - in separate parts of the garden - are healthy with no leaf drop/curl/yellowing, no bugs of any description and there has been no change in the way they are treated. Everything in their vicinity is doing very well. Yet the lilac flowerheads are few and far between this year; I have to say that those which are there are very healthy. We live in Newark...any ideas?