Q: My little frangipani plant just toppled over. The stem is all soft and rotted. I have some other ones that I want to protect from this. What can I do?
A: This is a disease problem and most likely a form of wet rot. Remove the dead plant and pot away from the healthy plants. You could apply a copper fungicide to the healthy plants as a preventative measure.
Q: What is wrong when leaves yellow and leaf tips brown on Dumb Cane?
A: On Dumb Cane or Diffenbachia the older leaves will yellow and die as new growth emerges. This is normal. If the browning leaf tips are on newer growth this can be a watering problem. Make sure the soil is kept moist but not wet. If you see a white crust on the soil surface or around the drainage holes, this is excess salt, Leach or repot the plant.