Hello! I have a diffenbachia that is about 5' tall. It is a long stem with 10-12 leaves at the upper . It has been healthy and happily growing away for years and it still looks happy and healthy. However, it has decided suddenly to not support itself -- it is not loose in the pot, it's as if the stem has gone soft and just bends. It will bend all the way down to the ground. I've repotted it with fresh soil, staked and tied it, and put a big rock next to the base to help keep it up. I do turn it frequently so it gets even light and I don't water too frequently...I wait until it feels dry but before leaves wilt. Have I done the right things? Do I need to do more or something else? I appreciate any help you can give...this has been such a happy plant in my house.

P n'P has the right idea. Dieffenbachias inevitably grow so tall that their stems can no longer support them. The only solution is to cut it back. I usually cut back to a height of one to two feet. That way there is lots of room for it to start over and grow upward.