I have a rubber tree plant that is about a decade old
About 1-2 leaves are falling off per day! Many off these leaves are only partially yellow or completely green. I have a water tray below it, so that it can drink as much or little water as it needs. However, it isn't taking any water. I usually fill it every four days, yet over the last 3 weeks the water level has not dropped at all. Please advise.
Certified GKH Gardening Expert
This article may offer some clues: https://www.gardeningknowhow.com/houseplants/rubber-tree/rubber-tree-plant-leaves-falling-off.htm
Presumably, if you've had it for 10 years, you haven't made any great changes in its environment. When ficus trees of any kind - the rubber tree is a member of the ficus family - start dropping green leaves, the first thing to suspect is too wet soil. "so it can drink as much or as little as it needs" is not the way potted plants work. Roots need to breathe; if the soil is constantly wet, which it is if it always sits in a puddle, the roots are basically drowning. Ficus trees tell us about this by dropping green leaves. Dig down into the soil with a spoon, all the way to the bottom of the pot, or use a moisture meter, or even a wooden skewer - you'll probably find it's pretty muddy down there. The good news is that if you let the soil dry down so that the roots can get some air, it should right itself. Let the soil dry till it feels just very slightly cool in your fingers, all the way to the bottom of the pot, then you can water again. Allow no more than 1/2" of water to remain in the saucer, and don't water again till that's all gone, and the soil is dry as described above. Your rubber tree should be ok.