I happen to have one ~ a very old one that bloomed so sweetly & profusely over the years but had moved her several times trying to follow the sun! In the last site I dug her out of, the trees grew all around & shaded her beautiful site in my front foundation. I pruned her severely to 18" after her scanty blooms & moved to a south exposure foundation & now she is as lovely as can be so full of bunches to burst as she used to, very soon!!! Be patient & give her losts of sun she should please as they usually do. BTW I've only added the usual cotton seed mulch when we moved her for the last time ~ 2yrs ago - lots of her roots even got chopped off in the move but Lilacs are not whimps!!!

If it doesn't get enough sun, it might not bloom. If it does get sun, ... don't fertilize it, ... don't prune it, ... but do take a spade and dig into the root-zone a bit. Don't dig it up ... or dislodge it ... just threaten it a bit.

I have one that had to be moved several years ago, into a location where it could receive several hours of direct sunlight. The old location was in my side yard and it bloomed well, until a nearby tree became so large that it provided shade for most of the day, whereupon it stopped blooming and the entire shrub began to tilt toward the brightest light. If I had not moved it, I think it would have eventually become horizontal upon the ground. LOL! A few years after it was moved and began blooming again, a daffy neighbor cut it to the ground. He insisted that he thought it was a Japanese privet and he was doing me a favor by cutting it down? It has since regrown and again blooms. See if you can find a location near the woods edge, where it can receive about 6 hours of direct sunlight. You might try it in a dappled shade location, but I suspect flowers may be sparse. Mine came from a local nursery, about 40 years ago, but I haven't seen them offered locally in the past 2-3 decades. You will probably have to Google for an online source. Be sure to check any vendor's reputation at GardenWatchDog before ordering. You will need to Google for that URL also, as posting it here is not permitted.

That looks like the Persian Lilac I bought at Lowes recently! I'm so excited that yours is doing so well. I happened to see one on my walk today. Asked about it and was told that the homeowner in his 80's brought it from the family farm in TX. Said that all the old farmers had them. Carrie, is yours in morning sun? That's what the tag said, but the homeowner this morning has his near the curb and it should bet a lot of sun and heat. sorry to ramble on. I've missed lilacs for decades and I'm still leaping for joy. c