I have a lilac that is tall but doesn’t blossom. In fact, it hasn’t blossomed in about five years. Hmmmm.... time to pull out the flame thrower! LOL!
Have you tried this?
Luke 13
6 And he told this parable: A man had a fig tree planted in his vineyard, and he came seeking fruit on it and found none. 7 And he said to the vinedresser, Look, for three years now I have come seeking fruit on this fig tree, and I find none. Cut it down. Why should it use up the ground? 8 And he answered him, Sir, let it alone this year also, until I dig around it and put on manure. 9 Then if it should bear fruit next year, well and good; but if not, you can cut it down.
I’ve heard lilacs love/need a lot of calcium.
You might try buying a bag of lime and spreading a couple pounds around the base.
Absolutely. Burn it down or at least cut it way back.