S/H Question Air Movement

[janice]

I have numerous orchids (several types) in S/H and have had good luck. However, in the last 6 months I repotted a Bllra. and a Onc. They are medium size - the hydro will look dry and reservoir of water almost empty but the roots are staying very wet.....and appear to be rotting......and I am not seeing new roots. The leaves and bulbs look healthy at the moment but this concerns me. Is this possibly an air movement problem?? Any advice would be appreciated. jan

[Phalcycle]

The transition from medium to medium can be stressful for orchids.
Because the medium they were in before didn't have the same moisture benefits the hydro has, the roots will often rot. That is why it is wise to transplant into S/H during Active growing, because new roots will transition better than old roots that are used to other mediums

[janice]

I have had pretty good luck with the transfers............and I hope this is just "transfer" stress.....but I don't like the looks of wet roots......we shall see?? These orchids were larger with more roots than my previous....thanks, jan

[Ray]

Jan,

One of the primary concepts behind semi-hydroponic growing is that the roots stay constantly moist and in contact with nutrient solution, i.e., they are supposed to be wet.

As Phalcycle mentioned, once the plant has grown new roots that are tailored to that environment, it will thrive, while we expect the old roots to die and rot.

Incidentally, that root replacement process happens in any change of medium conditions, even moving a plant from old medium into a fresh version of the same kind, it's just more of an extreme difference moving into S/H culture.

[janice]

Ray, thanks so much . These two orchids had so many more roots than my Catts. and Phals. that I previously switched to S/H and it has concerned me. They just are staying so wet...............and without new roots I have been worried. They appear to be rotting??? I hope this is a learning experience........jan

[Ray]

So when you repotted the plants, they were beginning to grow new roots, right? If so, there is little to worry about.

[janice]

Ray, one had new root growth and the other one did not. I had bought the Onc. from a Herb/Garden Show............when I got it home the medium was very very wet underneath.............and the medium very fine. I decided to try the S/H since it was a mess anyway. jan

[mehitabel]

Originally Posted by janice

...and I am not seeing new roots. The leaves and bulbs look healthy at the moment but this concerns me. Is this possibly an air movement problem?? Any advice would be appreciated. jan

Oncidium intergenerics form new roots on the newest pseudobulbs. If there aren't any new pbs, that's why you're not getting new roots. Anything you can do to stimulate growth so that new pbs start to form will help your plants get new roots.

I always found a few strands of sphag on top of the s/h medium encouraged new roots to form.

[janice]

There is a new pseudobulb......and it looks very healthy...........I will try a few strands of sphag. I really appreciate all the help from everyone. jan