Black and Sticky?!

We noticed that we have a few leaves on our Michelia Champaca tree where there is something that looks like black soot. I touched it and it's kind of sticky. Does anyone know what this is?

Thanks!
Nancy

Here's another view of that black stuff...

Look elsewhere on the plant (above the foliage with the "soot") for scale insects. Michelia is related to Magnolia, and there are scale insects which favor this family of plants.

As they feed on the foliage/stems of the plant with their piercing/sucking mouthparts, the scale insects excrete honeydew which will contain excess sugars. This honeydew lands somewhere (usually on foliage below the insects) and makes a great substrate for sooty molds.

This may be just what you are seeing on your plant. The sooty mold should wipe right off; the scale are a little more difficult to be rid of.

Hi ViburnumValley,

Thank you so much for the information. Although we didn't see any scale insects above or below the soot mold, we did see a spider web near the top and my husband saw the spider actually hide into the top opening of one of those bamboo stakes so we sprayed into the opening and haven't seen the web or spider since. I'm going to use soap and water and rub the black mold off the leaves. One other note is that we also saw some curling on a few of the Michelia leaves and wondered if this was also part of the mold issue - no black soot on these just the leaves sort of curling on one side.

Thanks again!

Curling leaves could indicate activity (present or past) of other piercing/sucking insects, like aphids. They are also accused excreters, and their honeydew could create the same condition.

At least it isn't getting worse.

the spiders are actually a good thing to have. they will catch and kill the bugs which are causing the sooty mold.

Yep - he WAS a good guy.........

Well shoot. I didn't mean to get rid of the good soldier. The tree is looking better but I still see a few ruffling/curling leaves on the ends so I'm keeping on eye on things.

Thanks,
Nancy

There are some spiders that will curl the edge of a leaf and make a web inside. But they do not eat your plant, they eat what's eating your plant...

Thrips will cause a distortion in the edge of the leaf - cupping, curling, etc. They are tiny insects that suck out the contents of a cell (or cells) and when the leaf grows, those cells are missing causing leaf distortion.