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Jade Plant Pests

January 27,1999
My jade plant does not look like it is feeling very well. Some of its leaves have brown spots as if they were scars. I do not remember seeing any of these brown spots when I first received it in december. I do not know if there is a pest feeding on it or if the plant is not happy in front of the window. If it is a pest could you give me some information on how to get rid of it.
Thank you very much.
Mealy bugs are difficult to erradicate

Jade Plant Problems

From your description of the brown spot as a scar, I almost think that the problem might be caused by droplets of water remaining on the leaves, when the sun hits.
The water will act as a magnifying glass and burn the jade, almost instantly, and it will leave an ugly brown scar.
I really doubt that your plant's trouble is the result of an insect problem.
At least from the 'brown scar' aspect, it just doesn't sound like it.
There are really only four insects that seem to infest Jade plants (Crassula argentea) with much regularity.
They are mealy bugs, root mealy bugs, scale, and to a lesser extent, spider mites.
  • Mealy bugs will be evident by their white cotton like covering. They are usually found in stem axis areas, or on the underside of leaves. If there are only a few, dip a q-tip in alcohol, and use it to remove the insect and cocoon. If it is a major infestation, it might be best to discard the plant. There are insecticides which will kill mealy bugs, but be certain that it is safe for use on Crassulas, because some of them aren't!
  • Root mealy bugs are obviously found on the roots. (well, duh!)
    Once again, they will be noticeable because of their cottony covering. They are very tough to control, and can infest an entire plant collection rapidly. The only total success I had with these varmints was to totally drench the soil with diazinon, and repeat in 2 weeks...I don't recommend this at all,,,,toss the plant.
  • Scale are related to mealy bugs. They have a waxy shell that protects them from most insecticides, so you are faced with hand picking or scraping them off. This is pretty easy if there aren't to many.
  • Spider mites aren't a common occurrence on Jades, but it happens! You will find very fine webs across the bottom of the leaves, or hold a white piece of paper below the plant, and give the branch a sharp rap.. If there are mites, you'll see scurrying little specks on the paper. You can usually take care of spider mites by giving the plant a bath with insecticidal soapy water.

Jade Plant in Bloom
Jade Plant in Bloom
Crassula argentea