Growing Orchids Under Lights

[Ron-NY]

I've grown a couple of mini Catts under fluorescent lights. The light at the center of the bulbs is stronger than at the end of the tubes. So placing the Catts in that position gives them more light intensity

[78Terp]

One of my catts under the 8 tube 4' lights got very yellow . So much that I moved it out of that light for more natural light exposure. It has gotten somewhat less yellow since I moved it and is growing new roots. My other catts under the lights seems to be doing ok. They all are (3) growing roots at a minimum and at least one has a new growth.

[OrchisAmor]

So, now I wonder what would be the best light source to grow Cattleya, since I do have one Catt.?

[Jx3]

Harvey, I won't say for sure because I don't know your exact setup but you'll probably find it very difficult to gett your catts to bloom under fluorescents. I've tryed on and off for years even putting them right in the middle of the bulbs and only 2-3 inches away. Don't get me wrong mine grew wonderfully tons of roots and new growth all the time, just never would bloom. Good luck though hopefully you have better luck than I did.

[raybark]

If you cannot get catts to bloom under lights, you're either not giving them enough light (too little wattage, and/or too far away), or the problem isn't light...

[Jx3]

Well if 6 40watt 4ft tubes aren't enough then I don't know what is, I've had no problem blooming almost every genera of orchid under fluorescent tubes just not catts. And my growing environment and culture are spot on, my orchids are very happy. I'm by no means saying its impossible to bloom catts under fluorescents, just difficult. Apparently I'm not the only individual who feels this way because I've spoken to many vendors and growers who agree as well as the boat loads of material in literature about growing under fluorescent tubes. But everyone has there own opinion so mine is that catts and vandas and other full sun plants won't grow to thi full potential under fluorescent bulbs

[raybark]

"6 40watt 4ft tubes" at what distance from the plants, and with what reflector? 40W T12 bulbs (I'm assuming that's what they are) put out about 1600 lumens. Six of them, therefore, will put out 9600, which is sufficient to burn plants, so more than enough for blooming, if properly placed.

I used to grow exclusively under lights, and had no issues with catts or vandaceous plants, but intensity hitting the plants is crucial.

I did some measurements of a 24W T5 bulb, with and without a reflector. The output of one of those is 2160 lumens, and I measured 2000 fc at the point where the reflector flanges end (about 1" from the bulb itself). At 6", it was down to 800 fc.

[Cape Fear]

i have a light cart and have recently purchased 2 48 inch T-5 HO 54 Watt lamps, one red, one blue.
I read in an earlier post that red and blue lights make plants look like aliens. What
are some other opinions on this matter? cape fear

[78Terp]

Never heard that. Mine look fine under the mixture.

[raybark]

I believe that was referring to the use of red and blue LEDs. With no green light to reflect back to the eye, plants look black.

I'm pretty sure you don't have red and blue T5's. Probably more a matter of white at two different color temperatures to skew their spectra toward red (~3000°K) and blue (~6500°K).