Help & advice please....4 years ago I planted 2 lilac bushes in different parts of my garden, for 2 years I had a lovely display from both and they appeared to be flourishing, but last year on both bushes part did'nt produce foliage, during the late Autumn I trim back the "dead" section, this year both appear to have died. Both, although a good distance away from, but are situated directly underneath the canopy of huge Yew trees, could these have contributed to my poor lilacs demise.
