My lilac bushes have over the past 2 weeks had the leaves turn a dark brown almost burnt color. Then they fall off. It started in a small area but has now spread throughout the row of them. I do not see any bugs on them but they do have a green mold type growth on the bark. Do you know what is causing this or what I can do to stop it and save them.
There are several reasons why this may be happening. considering how saturated the soil is right now due to an excessively wet summer, they may be suffering fro that. The algae on the bark lends that credence. The wet, humid summer also leads to fungal diseases so that might also be an issue. If you’ve piled mulch up against the bark, that can slowly kill them. If you have done that, get out there and pull the mulch away from the trunk several inches and keep it that way always. Mulch is good but not when it is burying or touching the bark. The most important thing is to make sure you rake up and remove the leaves as they fall to prevent any re-occurence next year. They should bounce back and be fine next year assumong we have closer to normal conditions. Here’s a link you may find helpful. https://gardensuperior.com/why-is-my-lilac-bush-turning-brown-and-how-to-revive-it/