Dehydration

Question

While my question concerns phalaenopsis in general, I have had this same problem with other orchids as well. It seems like when one of my phalaenopsis get a virus or scale, it stops taking up water and looks wilted. No matter what I do, it never recovers. I have had this same thing happen when I have under- or over-watered a phalaenopsis. What can I do? —Tina M. Swartz
 

Answer

Virus or scale probably has nothing to do with your problem; their occurrence is coincidental. Both under- and over-watering can cause similar symptoms. If a plant is underwatered, two things can potentially happen: The roots stay healthy, but have no water to take up, or the roots die as a result of excess salinity caused by the concentration of the soil solution and cannot take up any water. The result is the same in both cases: dehydration. If the plant is overwatered, the roots die, and the plant cannot take up any water. The result is the same as option two above: dehydration. If the roots are healthy and the plant is dehydrated, the medium simply needs to be re-wet by several waterings in frequent succession or by soaking the plant in a tray of water until the medium is thoroughly wet. Orchid medium can be difficult to get wet again if allowed to get too dry. If the roots have died, either from salinity or from rot, the only solution is to repot in fresh medium in the smallest pot that will contain any living roots. The plant should be kept shaded and humid, the medium kept barely moist, until new roots form, at which time normal watering may be resumed. —Ned Nash