Frankly, I think growers and orchid vendors should give us much more information on their plants.

I have never found artificial light to hamper anything except Poinsettia's. My plants grow in our living room with lamps, tv's etc. All summer they are on my deck with lighting all over. I've had other problems affect their blooming, but never lights.

Jane

As far as I can figure out, it's a few species catts that are day length sensitive. I don't think hybrids would be affected that much.

I read in Rebecca Tyson-Northern's book on orchids, that specimens with C. labiata in the background, (and possibly a few others) are a little sensitive to night-time light. That is why I am changing my routine with some of these plants. In retrospect, the ones that are blooming now have been on the side of the house that is dark at nightime (outdoors) and the ones that have sheaths but no blooms were on the other side of the house with a lampost shining on them half the night.....time will tell. Something to think of when you have a stuborn plant of these hybrids - maybe too much light at night. It makes sense though, if the change in day length aside from the temp drop is what triggers them to bloom.

I don't think lights from a distant street light or a single light to keep a room from being pitch black is what they mean by light sensitive. Doesn't the full moon also light up the night and sometimes quite brightly?

If the plant is growing under artificial lights and they run for 16 hours a day, then the plant will not have a trigger to bloom. It is the shortening of the bright light as the seasons change that signals the plant it is time to bloom. Many professional greenhouse growers will also have artificial lights in them to extend the shortened daylight hours to help plants grow faster.

Brooke

Lets be realistic. How many fc's do you think is being cast on a orchid from the TV or a street lamp? I'm with Jane on this.Ya gotta live! I am not walking around with a pin light, smacking my shins on the furniture for orchids!

We fry our orchids at close range underneath whatever we can get our hands on and that is still not enough light. Ambient light from another source is almost nothing. Many times it's the wrong colour. Windows filter, we have all heard this. I live in downtown Chicago and grow a mixed collection. Never had a problem and it is bright here at night.

Day length sensitive and fc's are different animals. duration of time vs amount/inensity of light. If you are growing under light, day length sensitive plants will adjust to your run time if you use tubes or low powered cfl's. Look up Howard's old posts. He describes in detail time/ duration vs footcandles. Howard were are you these days?

I never had a problem with bloom cycle on an equitorial plant because my run time was 14-16 hours a day. I grow many plants from the equitorial region. These are not wild collected plants we have here. They have been aclimated to "human conditions"

Clara

While I completely agree with you clara (I am also in downtown Chicago) I would remind you that some plants ARE sensitive to light (poinsettas and X mas orchids, and african violets come to mind)in terms of reblooming. I have an unobrstruced N window on the 9th floor with city views and in the middle of the night, all lights shine into my window. The phals and paphs do not seem to mind, but my friends who stay over do. (They say it is like daylight!)

What I was trying to convey was that according to Mrs. Northern, if you have a catt with C. labiata in the background, and it will not flower, keep it away from extraneous light sources since based on her research light does factor into the equation. I was just commenting that it might be worth to seclude some plants that will not reliably flower just for the hell of it.

I could never get all my orchids into a room where some evening light got to them, but for the catts that refuse to re-bloom I just might

Clara i never thought about it that way. see now that makes a ton of sense the street lights really cant do much can they LOL. and im supposed to be smart Hahaha. i dont know why that did not occur to me. cause in the wild they're growing in the canopy of the rainforest with the moon shining down on them and they bloom anyways and we have hybrids for petes sake. Haha well thank you for that

Samuel

Well, street lights had that effect for two of my plants, one half labiata, and a mossiae. My space is a 3rd floor sunroom, just about on a level with a big old vapor street light. Neither plant bloomed until I figured out to put them on the floor every night where they would be shaded. A street light is much brighter than the moon and is on for much longer every night. But on the 9th floor the street lights shouldn't be all that bright
This was no problem with other hybrids and with brassavolas.
Margo

It will be the Catt species which are fall bloomers where shortened day length is the trigger to bloom, such as C. bowringiana. If it is a hybrid, then it's a toss up although much depends on how much it carries of the fall-blooming genetics as to whether it will or won't be affected by light during the evening and nighttime.

What really upsets me is that how on earth am i supposed to know what genetic background my plants have. I mean no vendor lists a detailed list of all the plants hybridizational crosses. Thats what makes this so complecated cause how am i supposed to get a hold of that info. honestly i have no clue to the background of any of my plants. the libiata i believe is a main parent cross of red hybrids so my chia lin new city may have problems but im not worried about that because its roots went down the crapper overnight and it cannot take up water. So UNFAIR!!!!!! >:o

I AGREE!! Lets get a petition going...

Jane

That's why judges, breeders and hobbyists buy programs like WildCatt and OrchidWiz, so they will know a hybrid's genetics. You can do it yourself through the RHS website, going back generation by generation and creating a family tree for the plant. It can be time consuming though with complex hybrids.

I love OrchidWiz. Thanks to cj and others who mentioned it about a year ago. My husband got it for me, as I was hesitant to spring for it. I use it all the time.

Love to look up the "awards" where you can get a description of the very best ones of a cross, including the size of flower and how many at once. Also a description of what a dynamite grower can get out of a plant (the CCM awards). Also get an idea of the overall quality of the cross, and the variability it produces. Gives you a much better idea of whether you will like a plant.

And, as she points out, you can get the % species concentration (on average), which will give you an idea of what a cross might be like if you know what characteristics a species imparts.

Another function in these programs which can be helpful is looking at the dates of the awards. Sometimes it shows a composite that will help you know at about what time of the year it is generally in bloom, at least with the once per year bloomers.

The problem is not as bad as you might think. As far as short day (long night) light sensitivity goes the Catt. labiata genes don't seem to stop blooming, just move it later in the season if the wrong type of light hits the plant. Commercial growers used to hang strings of 100 watt light bulbs over the plants to delay blooming in order to have flowers coincide with holidays. This is pretty intense light if you think about it.

From a physiological standpoint all this type of light sensitive plant need is a very short duration of light at the right wavelength (red I think) at a fairly high intensity to set them back into thinking the days are still long. This is why moon light (blueish) doesn't cause problems, and why we don't generally have to worry about TVs, street lights etc.

The experiments identifying the triggering mechanism were done on very sensitive plants (not orchids), but it is still a good idea to shorten the timing of your plant lights a couple of hours starting about now so the plants think the days are getting shorter.

Thanks for the tip, cj. Just hadn't thought of using the dates like that.

And BTW, the orchiwiz guy is a really nice fella. He answers the phone himself, and helped me reset my computer for easier reading.