If your potted plant is looking yellow and wilted even though you’ve been watering it regularly, it’s possible that you’ve been watering it too much. Too much water stresses out your plant, makes it more susceptible to disease, and can cause the roots to rot. Fortunately, you still may be able to save it.
Move the plant to the shade, since it won’t be able to take in all the water it needs to be in proper sun. If the soil doesn’t seem to be drying out quickly enough, you can repot the plant entirely. (With succulents and other plants that need very little water, you can even leave the plant lying out on paper towels or something other absorbent surface while the root ball dries out.)
Make sure that your plant is draining well. If there aren’t drainage holes in the bottom of the pot, you can drill a few or else repot the plant. Mixing in vermiculite can help make the soil less dense.
If you’re concerned about root rot, repot the plant, dispose of the old soil, and sterilize the old pot. (Root rot is caused by a fungus, and you want to be careful to keep from spreading it to other plants. Wash your hands between handling infected and healthy plants.) You can try trimming away the diseased roots (they will be recognizable by their weak, mushy texture) or treating the plant with a fungicide.
We got our information on rescuing overwatered plants from Gardening Know How, Proven Winners, Ortho’s Guide to Successful Houseplants, and The Houseplant Expert: Book Two. Both books are available at the Newton Falls Public Library, along with others like Tovah Martin’s The Indestructible Houseplant.