To fix the problem, ease up on watering. Let the soil dry completely between waterings, and in winter, cut back even more.
You can also repot into a more appropriate potting mix if poor drainage is the issue. Use a cactus and succulent potting soil or follow our instructions to make your own.
4. Pest Infestation
Sap-sucking insects including aphids, mealybugs, scale, and spider mites can cause black discoloration on jade plant leaves.
They secrete a sticky substance called honeydew that encourages the growth of sooty moldwhich appears as black, soot-like patches on leaves.
Aphids and spider mites typically cause stippling while scale insects resemble small brown or tan bumps on leaves and stems and can cause tissue damage that appears as dark spots.
Mealybugs appear as white, cottony clusters and can also cause spotting as they feed.
Stressed succulents are more susceptible to infestations. For aphids and spider miteswash the leaves with a strong spray of water or wipe them down with a cloth dampened with plain water.
You can also use insecticidal soap for more advanced infestations, but make sure it’s specifically labeled as safe for succulents since jade plants can be sensitive to some formulations.
Scale insects can be scraped off with your fingernail or a dull knife if there are just a few.
For larger infestations, dab each scale with a cotton swab dipped in rubbing alcohol, or spray the foliage with a solution of one tablespoon insecticidal soap mixed with one cup rubbing alcohol in one quart of water. Repeat applications every three days for two weeks.
If you find mealybugs, use a cotton swab dipped in rubbing alcohol to remove them. Regular inspection is key to catching pests early before they cause significant damage.
Learn more about jade plant pests here.
5. Sunburn
Sudden exposure to intense sunlight, especially after being indoors or in low light, can scorch jade plant foliage.
While they need plenty of bright light to thrive, they must be acclimated slowly to stronger sun conditions.
Sunburned leaves develop dry, brown to black patches that may feel crispy or papery. Severely burned leaves may collapse or wrinkle before eventually dropping off.
Moving a jade plant suddenly from low light to bright, direct sun is the most common trigger.
Indoor specimens are especially vulnerable because window glass can intensify the sun’s rays. Even outdoor specimens can burn during heat waves if they’re not used to full sun exposure.
