Question about light at night

[Tschimm]

Search for "Photoperiod"

The origin of the plant can be a good indicator wether the plant is influenced by day length or not. The farther from the equator, the more it could be.

[isurus79]

Originally Posted by MamaLiberty

My orchids are in the upstairs bathroom. I don't use it a lot at night, but once in a while the overhead light will be used for brief periods, especially if I have company. I can't imagine that would upset the blooming of most of mine, and I don't know what in the world I'd do about it except issue flashlights to my guests.

Tell them to be quick. Number one only!!

[gngrhill]

Thank you all for your responses. All of mine are subjected to some ambient light at night. I have had my issues with reblooming, but I also have some that have rebloomed. So, I figured that it was definitely worth the question to other growers.

[Fairorchids]

Originally Posted by Ray

To my knowledge, it is primarily some cattleya species that respond to shortening daylength to initiate blooms.

I have to question the "streetlights or kitchen lights stopping blooming" as possibly being a myth (or excuse for some other cultural shortcoming). It, of course, depends upon the intensity of the light and distance from the plants, as the inverse-square law cuts the intensity drastically.

Plants don't need total darkness...

Ray,

Pointsettias are VERY sensitive. Plants will bloom, but they will not develop the colored leaves (which people think are blooms). In nurseries, you have to shade against the street lights.

I am not aware of any orchids that are sensitive to that level.

[Ray]

There is a wholesale nursery near me that does seasonal plants, and they have the entire property is very well lighted with streetlights, yet they have no problems with getting poinsettias to "color up", which is why I equated it to intensity...

As an aside, I had a chance to spend some time with Merritt Huntington years ago (I lived in DC and went to Ga Tech with one of his sons), and there were whole benches of cattleyas that were covered with black cloth after a certain time in the afternoon, specifically to "shorten" the days and force blooming out of their natural season.

[Joseia]

I have always wondered about this. I have some cattleyas that look great, lots of bulbs, but have never bloomed in my house. I know they are getting plenty of light. I took one of them to my office, a BLC Windward Flare (office is totally dark at night) and it bloomed three months later. Maybe it would've bloomed at home anyways, but now the rest of the catts are in the office too.

No problem blooming dens, phals or vandaceous in the home.

[GardenTheater]

I have Catts in my master bathroom window. My husband and I both turn the lights on at night. Most have rebloomed for me more than once. Sounds like they'll like your office better.

[gngrhill]

Originally Posted by Fairorchids

Even faint artificial light, such as a street light, can ruin the blooming cycle in Poitsettias.

I wonder who pulls the shade when the full moon is out

[Leafmite]

This is a pretty good topic.
I have a C. walkeriana and some of its hybrids. It will be interesting to see if they will bloom under my conditions.

[Tschimm]

You mean because you're growing under lights ?