in every post.. add your big city location ..

lilac buds are there the fall before.. as long as you dont prune in fall.. once they are developed.. you are ready for bloom come spring ...

however.. many times winter.. early fall freeze or late spring freeze can kill the buds ...

if as you say.. they were pruned mid summer.. basically right after bloom .. they should have bloomed in spring..unless winter got them ..

and i cant speculate on that.. because is dont know where you are. ... or i missed it..

all i know.. is in my MI adrian ... all the lilacs were weak this year.. and it had nothing to do with your garden dudes .. and sometimes it isnt the winter that are horrifically cold.. but the borderline winters that are actually mild... that cause the most problems in my area /..

in other words.. if the plants go in and out of dormancy in winter.. with freezing in between.. you can lose those tiny buds ....

ken

Thanks, ken! I'm in a Chicago suburb, northern Illinois, which I think is zone 5b. The landscapers pruned the Miss Kims last summer and then again in November, so I'm not sure if they decimated the future buds or if our cold weather did them in. In any case, the landscapers will be back again in fall, so I'll ask them to skip the lilacs, just in case, and see what happens in spring.

If they pruned the lilacs in November they probably removed the flower buds for the following spring. It rather sounds as if your landscapers don’t really know what they’re doing. Or rather they do know what they’re doing. They’re making money from you by carrying out unnecessary work. Lilacs don’t need routine pruning. They can go years without any. Deadheading is ok, if you have the patience, but that’s about all. I would leave the long growths. The plants will even themselves out if left alone.

Agree with floral. Like all lilacs, Miss Kim blooms on old wood. Pruning back too long after the bloom cycle has ended - and certainly as late as fall - will remove the next season's flowers. And a hard pruning at that time can delay flowering for as long as 3 years.

If you must prune, do so lightly immediately after the plants have flowered. But they do not really require it.