I have had a lilac bush for about 6 years. Until recently been as good as gold. It bloomed in Spring but now it is June the leaves have died and dropping off like it does as if it was winter. Why please.
I dont know anything about lilac, only just got my first ever one, but I did see somewhere and I think it was on here, that they can get a disease, type lilac in the search box at the top of the site page and maybe you can find the old thread. Sorry I cant help you, maybe you could put a photo on.
Can you post a picture please wrinkly, to post one click on the green tree icon on the toolbar above the dialogue box, I'm sure you'll get help once we see it.