Bottom Heat + New Roots + Heat Mats Alternative.

[empiref]

Originally Posted by Ray

I think that if your air temperature is 13°C, your plants will be more-or-less dormant anyway. Their metabolic rates are controlled to a large extent by temperature, and at 13°, most tropical plants are "going nowhere", so transplanting them, then keeping them at that temperature is likely to be unsuccessful.

Certainly boosting the pot temperature to 28° will help, and no-doubt, will boost root growth.

Thank you Ray, The temperature is low at 13c because we have a snow storm. I have moved the Orchids into the living room where the temperature during the day varies between 23c and 28c because of the heating. I'll keep them there for a couple of weeks until the storm is over.