Q.What Is Wrong With My Joshua Tree?
Hi, my Joshua tree is started turning yelow an then brown. Am i watering it to much? Plant is now 2,5 years old, I was watering it every 10 days. Plant is in a special soil for Cactaceae and it is placed inside with constant temperature of 22C. I placed small rocks at the bottom of the pot for the drainage.
Thank you for your help.

Certified GKH Gardening Expert
I suspect that it is overwatered. When you say there are rocks in the bottom of the container for drainage, are there also drainage holes? If not, I would get it into a pot with drainage holes. Also, adding a layer of rock is no longer recommended. Joshua trees do need more water when they are young, but as they mature, they need very little. While your tree is far from mature, I still would try cutting back on water, let the soil dry out between waterings. Also, the trees are susceptible to fungal issues and attack by insect pests. See this article for more information:
https://www.gardeningknowhow.com/ornamental/foliage/yucca/joshua-tree-information.htm