|for the past 3 years my lilacs haven't bloomed.
The leaves loose color and drop off by midsummer. I live in the northeast. They are planted on the top of a sloping perenial garden. Is is possible that the perenial are taking all of the nutrients away from the lilacs?
|It sounds more like drought stress to me. Although your lilacs are planted at the top of the slope, it's possible the water is running down the slope rather than soaking in to the soil. I wonder if you dig a basin beneath each of the lilacs to catch water if it will make a difference? I think it's worth a try. Try building up the soil, sort of like a shelf so the soil is level beneath your lilacs. Make each basin about 12" out (or around, depending upon how your lilacs are situated on the slope). The goal is to have a 3" deep, 12" - 18" wide watering basin for each plant. Fill the basin with water, allow to drain, the fill a second time. Do this weekly throughout the growing season. Watering in this way will concentrate the moisture directly over the root system and allow it to slowly percolate down to wet the entire rootmass. Feeding isn't required with lilacs but you might try a light application of 5-10-10 or similar low-nitrogen fertilizer. After the normal flowering season prune your lilacs back to encourage healthy new growth. Lilacs develop flower buds for the following spring's floral display during the summer months. Pruning in late spring/early summer will encourage new, and hopefully, flowering stems. Best wishes with your lilacs.|