Blackened brasso cattleya leaves?

[SilverShaded]

Originally Posted by euplusia

A winter minimum of 16°C would do it, however 18°C are better. Our winter nights are long.
In October I made an experiment with 4 virused well established Brassocattleyas. I put the pots outside for 3 weeks. Nights were mostly 2-3°C, and many times the pots were wet from pouring rain. To my surprise the plants did not suffer at all. Not the slightest damage. So I put them in again.

Not sure what to make of that. They are ok at 2C but 18C is better?