I agree with 14+,the dead Lilac-blooms have to be dead-headed..
I had a Lilac that never bloomed and a friend,kind of an expert on Lilacs,said to cut the blooms off as soon as they are dead.
He also said not to prune the actual tree(bush)or you'll cut off next years blooms.
If you are near to a Costco,they usually sell their bulbs in large bags,but it might be easier to order from a catalog.
With Roses,I always deadhead them and in the fall cut them right down to about 1 foot,I might just dig them up,they look terrible right now..
"The cruelest animal is the Human animal"
3 kitties,Rocky(r.i.p my boy),Chico,Vinnie