Saturday, August 14, 2010

The perils of excessive heat and sunlight for cool growing orchids

It's been a hot and humid summer here in Toronto.

Last month, during a particularly intense run of hot and humid weather, one of my cool growing orchids suffered some possibly irreparable damage. Pleurothallids are normally cool-growing. This one was in my upstairs studio / orchid room. Temps on the upper floor of our house probably hit over 35C / 100F during a four or five day period. We weren't using the AC consistently over that time, and even if we were, the upstairs stays quite warm. I forgot about the face that I had some particularly sensitive and cool-growing orchids up in that room, namely two species of Pleurothallids: a restrepioides and a phallangifera.

The restrepioides seemed fine and as soon as I realized the danger / damage, I moved it to a cooler, less bright spot on the main floor. But the damage was already done to the phallangifera. It lost most of its 30 leaves the day I discovered it. There were a couple green ones left, but its last leaf feel off a few days ago. It had at least 30 leaves, and they turned, within the space of just a day or so, various shades of yellow and brown. Unfortunately I don't have a picture of the plant before it was damaged! Below are pictures of the progressive loss of leaves. I'm hoping that once the plant gets over the shock and hopefully recovers, it might start growing some new leaves again.