Question
I have a indoor yucca tree over a year, recently, the pot plant area smell like cat pee, I watered it many many times, tried to rinse out the smell,but seems doesn't work at all, all the water came out from the plant was dark and smell.
Why is that? and what I can do? please help. thank you

Answer
It sounds like you have over watered the plant and the roots are decaying. Here is a answer from the indoor plant expert.

"Let the exposed area dry out. It sounds like your plant is rotting for some reason. I would remove the branch that is rotting (the one that has become soft). Whatever you do, don't water it. Let the soil dry out completely before you water it again. Yuccas generally only rot from too much water or if they are exposed to too much heat, not a problem this time of year.

After your sure your yucca is no longer rotting (probably 3 months from now), replant it in fresh soil in a new pot. Once they start to rot, there will be bacteria in the soil that will continue to affect your plant. Knock as much of the dirt as you can and sprinkle powdered sulfur on the roots."