orchid yellowing leaves

orchid yellowing leaves
Can anyone help me with an orchid?

All I know is that is a Dendrobium orchid. Apparently the yellow leaves? Be which is not good. How – I resolve this problem.

I thought my orchids and I lost! Basically, do not act in time, my plants developed root rot. what happens in many orchids that are not sold with the proper support for growth. orchids need to be moist, but also a chance to dry, especially during the winter months, which are not capable of doing if they are potted with any type of foam or other undesirable materials. All they need potting bark, which can be found almost anywhere that sells plants and planting of other goods. It should say "orchid" the bag is about 3-4 dollars a bag here and give enough of everything in the pot some plants. You can also use it as a hat "to other plants in pots on the ground is very nice! Hope this helps!