Black Spots on my Jade plant

My Jade plant is doing beautifully after spending the summer outside. I'm about to bring it in for the winter but have noticed black circular spots on some of the leaves. I'm wondering what this is and how to treat it. Could this be some sort of fungus like the black spot that's found on roses?

Is/was it located under a tree - a maple or ash, perhaps?

Al

Thanks for the reply, Tapla. No, it's in a pot on my covered porch.

Can you rub it off if you rub gently?

Al

Just went and gave that a try and no, it won't rub off. In fact, it seems to be working its way into the leaf. My two suspicions are fungus or mealybug.

I was headed toward sooty mold growing on honeydew from scale, aphids, or other insects. It often falls from trees (honeydew) - thus my question. That's not it, though.

Yes, probably something fungal or perhaps one of the bacterial leaf spot diseases. You should remove & destroy the affected/infected leaves & treat with a home anti-fungal. Baking soda is always good. Try 2 tsp in a solution of 3-1/2 cups water & 1/2 cup milk along with about a half tsp dish detergent. Apply by spritzing. You could also use chamomile tea as the water part of the mix.

Remember - this doesn't cure things fungal - only prevents them, which is why it's important to remove infected leaves. Sunshine also help considerably, but remember to introduce your plant to full sun gradually to prevent sunburn.

Al

Thanks Al. Great advice. I appreciate the homemade antifungal recipe and am off to mix up a batch. I wonder if the fungus has come as a result of the extremely humid conditions we've had this summer. I'm afraid that quite a few of the leaves have been affected.

Perhaps that, but direct sunshine is a good anti-fungal in itself. Additionally, your plant is probably stressed & weak from growing in deep shade, which makes it more susceptible to insects & pathogens. It prefers full sun. ;o)

Al