Cattleyas and late-night lights

[NEslipper]

Curious what other indoor growers have experienced regarding cattleyas being inhibited from blooming by indoor home lights after sunset. I have a bunch (mostly floofly white bow bells-type hybrids) on a bright south-facing window in my living room, where I tend to stay up late reading/watching TV. Lots of big, healthy green sheaths, but so far no buds. I have a few in an east-facing spare room that I almost never go into, and some of those are pushing up buds. It's anecdotal, but I find it surprising that normal house lights would be able to throw off the bloom cycle. I'm wondering if I should move some to the back room for a few weeks to try to force budding. Anyone else have experience with this?

 

[Ozpaph]

consider, also, if there is a temperature/light intensity differential in the rooms.

 

[abax]

I've "read", not experienced personally, that even street lights can disrupt blooming
cycles. I have no idea if it's true or not. I'm thinking temperature, light intensity as
well.

 

[My Green Pets]

I have only heard of walkeriana and labiata as being photoperiod-triggered bloomers.

 

[DrLeslieEe]

In my experience, certain species will be affected if the light is bright enough (on leaves) to prevent the dark photoperiod. If plants think its still summer because of the extended 'day-length', the fall and winter blooming plants won't bloom. It has only affected species for me, like labiata, trianae and schroederae. Most hybrids do not have this sensitivity but if they do not show buds, I would move into dark to test for one month. The temperature drop (6C/10F) is also necessary.

The light that prevented the aforementioned species to not bloom was a 100 watt table lamp with round shades 2 feet directly above the plant that stayed on from 7 pm to 2 am throughout fall and winter.

 

[NEslipper]

I've "read", not experienced personally, that even street lights can disrupt blooming
cycles. I have no idea if it's true or not. I'm thinking temperature, light intensity as
well.

I have come across this as well. I find it difficult to believe that streetlights would have enough intensity at the correct wavelengths to throw the plants off, unless you set them up directly underneath it.

 

[NEslipper]

In my experience, certain species will be affected if the light is bright enough (on leaves) to prevent the dark photoperiod. If plants think its still summer because of the extended 'day-length', the fall and winter blooming plants won't bloom. It has only affected species for me, like labiata, trianae and schroederae. Most hybrids do not have this sensitivity but if they do not show buds, I would move into dark to test for one month. The temperature drop (6C/10F) is also necessary.

The light that prevented the aforementioned species to not bloom was a 100 watt table lamp with round shades 2 feet directly above the plant that stayed on from 7 pm to 2 am throughout fall and winter.

Thanks for the detailed info! It sounds like you set up a systematic test of the photoperiod and indoor lighting.

Of course my trianaei are the closest plants to a 75W lamp (with shade), but they’re still maturing second growths so I’m not too worried about them yet. Interesting that hybrids don’t have the same sensitivity, even if they have a lot of the sensitive species in their background.