Could it be your mix? or perhaps a lack of air circulation &/or cold? Were they overpotted, that could do it too or a combination of all of these factors, sorry.

I do not think it was any colder in my garage this year than in past years and there is a ceiling fan, so I feel the air circulates fairly well. None of the plants were overpotted.

I wondered about the soil mix. Last year I bought a new brand and did not really like it; it seemed too dense and clumping even when I added in perlite,etc. It has been used up now and I do not plan on buying that type again.

Thanks for your suggestions.

Elsier,

I can guarantee you that your rotting Sans were a direct result of watering during the winter. Here in Texas I put at least seven 3-gallon containers full of Sans trifasciata in our garage during the first week of December and don't take them out nor do I water them until I take them out of the garage about 3 months later. You may not believe this, but the Sans survive nicely in the garage through the cold part of Winter with hardly any light other than about 5 minutes a day when we do laundry and have to turn on the light.

You might ask how can Sans survive 3 months with no lights and no water? I often think of this period as their dormant period when in their natural habitat.

For my rarer Sans (the ones from Kenya and Somalia) I leave them outside until just before it rains or freezes, then I bring them inside the house until the Winter rain or freeze is over, then I take them outside again.

Good luck.