Stuff on jade plant leaves

Asked September 6, 2020, 2:52 PM EDT

Hello! I noticed white/grey clusters of "stuff" on the leaves of my jade plant that weren't there before. I wiped the leaves off with a damp cloth, and found that the marks didn't go away, but revealed dark grey/black underneath. I'm worried this will harm/kill the plant. Is this cause for concern? What should I do? Do you know what is wrong?

New York County New York

4 Responses

Could the white/ gray fluff have been mealybugs? They are sap-sucking insects that love jade plants and would leave behind scars on the leaves. It could also be a type of mildew caused by Sphaerotheca fungus that causes corky or crusty patches to occur on crassula leaves. You can also get leaf pitting due to temperature shock, often from air conditioning proximity.

I don't think they were mealybugs? I did notice small gnat like flies fluttering about the plant at some point. If it is a fungus, will this kill the plant? Since wiping the white/grey stuff off, it hasn't seemed to have returned... There is still "pitting", I suppose (as you put it). Will this scar the plant forever?

I also noticed that (on another plant) there seems to be something happening to the leaves... They get these spots, and turn yellow... I've been plucking them off when they do so—but would you know what causes this, and identify what kind of plant it is?

I don't think they were mealybugs? I did notice small gnat like flies fluttering about the plant at some point. If it is a fungus, will this kill the plant? Since wiping the white/grey stuff off, it hasn't seemed to have returned... There is still "pitting", I suppose (as you put it). Will this scar the plant forever?

I also noticed that (on another plant) there seems to be something happening to the leaves... They get these spots, and turn yellow... I've been plucking them off when they do so—but would you know what causes this, and identify what kind of plant it is?

The pitting may get somewhat better as the plant ages but is likely to remain visible. The yellowing leaves on the other plant probably indicates a soil moisture problem. Your crassula needs to be in fast draining soil, in a pot with a drain hole and not allowed to sit in water run off. If it has been in the same pot for some years, check that the drain hole isn't blocked and the soil is not compacted. Water thoroughly, allowing the water to run from the bottom of the pot and checking back after 15 minutes to remove any water sitting in the plant's run-off dish. When the plant is in active growth, allow the soil to dry completely between waterings. In the low-light conditions of winter (October through February), water only as often as is necessary to prevent the leaves from puckering.