Good afternoon.. We have a lilac bush we purchased at a box store 4 years ago. It has grown a few feet and now stands at just under 5' tall. Each summer it gets heavy foliage but zero flowers. I have read that over-fertilyzing can cause this but we have not used much fertilizer. In spring of 2019, I used Miracle Grow (a blend for both flowers and veggies) and last spring, I used fresh grass clippings, around the base, as a mulch but i have made no other attempts to fertilize. We have no other lilac bushes on our property or neighbor's properties. We have a mixture of perennials and will add annuals each spring but most of these flowers are a few hundred feet away from the lilac bush. It's closest neighbors are two pine tree's immediately to the east and west of the bush, the limbs of these trees are approx 10' away on either side. To the south is a large field, typically used to grow soybeans, corn or wheat. To the north of the bush, aprrox. 20' from the bush,, I have a small veggie garden that I typically have at least one annual flower or two growing as well. I am wondering of the lack of another lilac bush close by is our problem, or maybe I should reconsider fertilizing? Could my neighbor (growing the soybeans etc) spraying his crops for pests be a cause of my lack of flowers? Thank you in advance for any advice you can provide.