My dumbcane is dying and I don't know what's wrong with it, please help... I thought I am watering too much, so now I am watering less frequently (the soil is not dry though) but it's still losing leaves ... Could this be a bug? I don't know if this makes any different, but initially (around late November - early December, as in the first photo) the leaves would get yellow at the tip and then fall off. Now a yellow/brown spot appears in the center of the leaf and spreads until the whole leaf falls off (three leaves at different stages of dying are shown in the second, third and fourth photos)... The good thing is that new leaves are growing, although older leaves are yellowing much quicker.... Appreciate any help! Nanso
Overall, your Dieffenbachia looks fine. Leaves don't last forever as Natureman said. Being an aroid, the plant prefers very well drained soil and diffused light. The potting soil should be composed of a good potting soil, peat, Perlite and possibly some orchid bark with charcoal and gravel to keep it loose. As long as the soil is kept damp (never soggy) the plant should grow fine. Fertilizer should be added but only in a dilute form and don't' try to over fertilize. Being tropical Dieffenbachia doesnt like cold but in your part of the world that is not a problem. Just keep it away from direct sunlight and the plant should prosper.
Just to be on the safe side, you may want to check for spider mites. Pay especially close attention to the undersides of the leaves and at the axis (where the stem of the leaves meet the stalks). On the leaves, spider mites will look like tiny specs. Oftentimes red or white. At the axis there could be webbing.
