vanda root question
 

I've had these two vandas for about 15 months now.
the one on the right has its first spike and bloom as you can see. Very excited.
My question is about the one on the left.
As you can see there was a good root system at the bottom but now this seems to be drying up. there is a healthy root growing about 5 inches up from the original ball and all the lower leaves have fallen off. My question is - should I trim off the bottom roots and let the new upper system grow or just keep spraying both.
These are my first Vandas and my first post.

I have about 15 vandas in my collection and they all grow differently. Some do poorly when the humidity is low but others don't seem to be effected. Some drop leaves if the temperature goes below 55 F while others don't seem to mind. Some grow tons of roots and others grow just a few roots. I wouldn't cut off the old roots until they're completely dried out and obviously dead. It doesn't hurt anything to keep the roots on the plant, even if they're dead. Water them as much as you can. They'll do best if the roots get watered every day or at least every other day. They may not die with less frequent watering but they'll do better when watered often.

I had a similar problem with my vanda, and I ended up making a cedar basket for it and potting it in a mixture of lava rock, charcoal, coconut husk chips and sphagnum. I also put a 23 watt CFL bulb right next to it. The leaf drop stopped immediately, and new fat root tips are growing from the old thin roots.

I see that you're also in Canada - vandas are a challenge in our climate and indoor conditions. Bare root works only in greenhouses.

That must be frustrating for you. I have a few vandaceous plants myself but one two true Vandas. I have one like you where the plant just grew weird. What I can tell you is that I upped the amount of water it got and now it's restoring itself both top and bottom. I grow inside under t5 lamps and have an ultrasonic humidifier blasting away at these plants. It benefits the whole room of course but the vandaceous plants are the happiest now. I'd do at tucker said.

observe the color of the roots on the right and then compare it with the sick Vanda on the left that only have two healthy roots....
you need to spray the left Vanda with physan 20 or if you dont have that; use lots of hydrogen peroxide...I dont know but it might have been exposed to cold and damp and developed a fungi or bacterial infestation and the result is the root rotting....the fast falling of the leaves means the plant is using leaves for sustenance not from the roots because the roots are coated with layers of rot....
please do not cut any roots in any of your Vandas, some orchid growers cut Vanda roots for aethetic purposes and to make it manageable for shipping in standard boxes....the outer layer of the roots may be infested by rot but the inner root might still be alive....you can eradicate the bacteria or the fungi but it will take you years to develop roots....

---------- Post added at 06:50 PM ---------- Previous post was at 06:42 PM ----------

observe that there is a fat pencil like root coming out of the upper stem; if this infestation worsen you can cut the bottom part an inch below from where the new root emerges....
but hopefully you can catch this in its early stage of rot....and please isolate the sick Vanda from your other orchids
tip:
* bright shaded sun light, warmth and humidity for Vandas at all times; there is no rest period even in winter....