Lights for growing cattleyas
 

Apologies if this question has been asked before. I'm new here and new to growing orchids under lights. I've spent a good amount of time going through the forum and other sites trying to find the answers and feel a little overwhelmed. So thought maybe I should ask a more direct question. I have a lot of experience growing endemic Vandas and Dendrobiums but this was when I lived in Sri Lanka (very strong light and high humidity)

I have a Cattleya that I would like to bloom (would probably be adding more). Currently the leaves are dark green which suggests to me the plant needs more light. It does look happy. Plenty of roots and two new pseudobulbs. My apartment gets very little light. Direct sunlight is limited from 10-11.30am and then its shade. I have some Phals that seem to like it however and they have bloomed well. I would like to setup some artificial lights and need some recommendations.

I would like to stick with LED's (no CFL's please). Going through the forum it looks like some of you like the ikea VÄXER lights? Are these good for Catts? Any links or recommendations will be very welcome.

Apologies for repeating myself. Sunblaster LEDs are great!

Where do you live? For Catts there may be a question of how many hours of lights you have, as well as intensity. Retail product availability varies by what part of the world.

Currently living in NYC

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Any chance you can provide some links to actual products? I'm a complete novice. Google brings up a ton of different products for sunblaster LEDs

Page not found - SunBlaster Lighting sale.products/grow-lighting/led-strip-lights/

I got mine from Harris Seeds, who happen have them on sale. Harris Seeds: Vegetable Seeds, Flower Seeds, Plants & Growing Supplies

My Catts bloom under them.

Your first link doesn't work.

Is this the product you mean?
Sunblaster 4' LED Light Strip 6400K






– Harris Seeds

Well, ES, sorry about that. I guess it didn't translate. Harris has all sizes, more than Amazon.

Here is a link to the lights I bought:

Technical Data - SunBlaster Lighting

I bought mine through amazon.

A lot of people in northern climates have insufficient daylight hours in winter to bloom some orchids. This is one reason people use artificial lighting: not only to increase intensity, but also day length. Most orchids are from the tropics, so something approximating a 12-hour day is often used. It doesn't matter whether you add the extra light to the beginning or end of the natural day. When I lived in St Louis and brought all my succulents in for the winter, I had the lights on at night and off during the day, so I would be able to spend time with my plants after arriving home.

That is interesting. I would have thought something like circadian rhythm would be important? unless of course the plants were in a darkened room. In anycase I intend to only use the lights in daylight hours

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Seems like theirs a lot of love for the sunblasters. Any other brands? or should I just get the sunblasters? I measured my setup and I think a 2ft strip light or a couple of bulbs in fixtures would be perfect

Check out Hydrofarm and Hydrobuilder. I've bought from both.

All three are good. Be careful what you ask for: this light conversation can quickly turn very technical and you will become needlessly confused.

I am just starting to make the switch from fluorescent to LED lighting. The sunblaster was the first LED lamp I really like.

I bought ActiveGrow LED fixtures, from Harris. I think they are similar to the Sunblaster. There were some videos on the ActiveGrowLED website that persuaded me. They showed the spectrum of the lights and the CRI as 91. So I went with those and so far I am happy. I have only had them running for about 6 weeks. I am seeing lots of new root growth.

Great! Glad you made a decision. For us, Harris has been good to do business with.

So, Dollythehun, I was so happy to read that you wrote that your cattleyas are blooming under your Sunblasters. After I put up the LED's I bought "a few" little Catts and have been anxious about -- is this really going to work? So I was really happy to read that it does work! Would you mind elaborating on your experience -- how close to the lamps are the plants? hours per day? I have mine quite close and 16 hours a day at present. I am getting about 1800FC +/- a couple of inches below the lamps at the center of the fixture. It seems like that should be enough but I'm a worrier and it was great to hear that you have had success! Tell me more!

My orchids are in our sunroom. It has east/south window combos. However, in Indiana, we have little sun during winter, and there are large trees for summer shade. The room was bright but generally not sunny enough. I could bloom oncidiums.

I first put in t5s overhead. Then a strip per shelf and then two strips on the bottom. The highest light plants the on the bottom. The distance a vsrues according to the plants. If they need less light, they go toward the back, front, or sides. The Catts are directly under and maybe 6" away.

Many go out for the summer, which helps. My current problem is space and light for the taller cymbs and Epis. I'll be reworking the room this fall but plan to keep using the same lights.

That's all I can tell you. It's not a precise science here. I have good instincts and read the OB a lot. Good luck.

Thanks Dolly. Similar conditions here -- sunroom faces south and east but doesn't get direct sun. Enough to bloom oncidium, miltoniopsis, barely. My light set up is in the basement. Was interested to read that you keep your cattleyas 6" away from the lights. I have mine closer. Maybe they don't need to be that close. As you say, observe and adjust.

You'll notice a change in leaf color. They should be light grass green. Too dark, not enough, too purple, too much. A tinge of purple seems to be my sweet spot. But this is only my personal experience.

Just to update everyone on my situation. I tried the sunblasters and they do not put out enough output for my use. I realize now, going through the thread that most people use sunblasters to supplement sunlight. In my case my windowsills are in heavy shade for most of the day. I did some research and figured that I needed at least 4 sunblaster lights running to get the kind of output to grow Catts. I ended up buying a COB LED light from Timber. The cost was cheaper than what I would have payed for 4 sunblasters. Still substantial (for me at least) but I figured might as well do it right. I'll update the thread with some pics once I have the entire thing setup

I'd love to hear an update on this...I am in nyc also and am in the process of planning to setup lights.

I have another light on order coming in next week. I will post a pic of my setup then. The light I have is fantastic. The plants are responding well and everything is a nice healthy green. I ended up badly burning a few leaves too. It's really super bright. It also does not put out any heat so I can touch the fixture after it has been on for 12hrs straight. Highly highly recommend these newer LED COB's

Which model are you using?

[QUOTE=stompy;880012]Just to update everyone on my situation..... I did some research and figured that I needed at least 4 sunblaster lights running to get the kind of output to grow Catts. I ended up buying a COB LED light from Timber.

Stompy: I'm very grateful that you posted about Timber. I'm so excited by what I found on their website that it makes me wonder if I need a Real Life. But nevermind. I jumped the gun a few days ago on having a completed setup, and ordered a seedling Catt. trianae on faith. Now I think I might actually have a chance of bringing it along. Thanks.

[QUOTE=aerides;886282]These lights really are fantastic. I have now sucessfully bloomed multiple Catt hybrids and even a Vanda. Very happy with them

Stompy, did you go for the 3500K?

I bought the 3500K also yes. I have both 6.4K and 3.5K lights running now. Some of my plants get mixed light the others get only one type. Overall all the plants are happy. I don't think the color temp effects things all that much.

Thanks. Good to know. I have to live with the lights that my "bedroom" collection receives. Done a fair amount of reading. One of the more trusted sources stated that 3500 has "plenty" of blue spectrum for plant-growing purposes. I'm using 3000K general floods and stuff is growing. Those plants are at a window (albeit a shady one) but it should help with blue anyway. Thanks for getting back.

I think the spectra depends on the LED type that's used. So you can have 2 LEDs that arecolor balanced to 3.5K but puts out very little blue vs the other puting out more blue. Check the spectra of the LED's. I made sure to check the timber ones before I bought

This answers a question I've been holding onto for quite awhile. Thanks.

Color temperature in degrees Kelvin measures the appearance of light color to the human eye. Color temperature was never intended to measure utility for growing plants. With LED lights color temperature provides no information on whether the light is good for growing plants. You need to look at other measurements.

On a practical note, any fixture designed for growing plants should provide a spectrum useful for orchids. Intensity of light emitted, measured in foot candles, lux, lumens or moles of photons per square meter, is very important. Most people figure it out by buying a fixture, putting the plant under it, and watching what happens. With plenty of light, orchids begin turning purplish. Dollythehun mentioned this above.

Understood, but spectrum analysis also seems central to any serious conversation about plant growth. Grow light vendors are not necessarily trustworthy regarding spectrum analysis. And many experienced orchid growers are receiving good results from household LED bulbs. I am coming to understand intensity measurements for LEDs in a practical sense, which has been comforting. But not making any real progress for detecting the actual spectrum of a LED bulb for practical purposes. I've seen videos of people waving a handheld instrument under a grow light fixture and apparently capturing a picture of the spectrum. What are those things??

I believe the instrument you are referring to is a par meter and the price of those instruments are expensive for the professional ones.

As has been stated, the color temperature of a fluorescent or LED lamp is how it LOOKS to the human eye, and not what the true spectrum is. All white LEDs are UV or blue diodes that have a phosphor that absorbs those wavelengths and emits wavelengths that combine to appear white. All such LEDs have plenty of blue, but little red.

Actually, a PAR meter tells you the volume and rate at which the lamp emits photons between 400 & 700 nm, but no information about the spectrum. It can be all red, all blue, white, or any combination in between, and the reading from a PAR meter can be the same.

Ideally, a PAR meter in conjunction with a spectrophotometer would tell us everything we need. I doubt any of us can afford that.

The manufacturer may have spectrum information available that is not on the retailer's Web site.

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An uncle sold GE commercial spectrophotometers in the 1960s-1970s. He did well.

Deceptive appearance
 

Fascinating statement, Ray. Just to be clear, are you saying that even though this phosphor you mentioned masks blue wavelengths for appearance sake, that these wavelengths are nonetheless being emitted? This shows me up embarrassingly in what I don't know about light!

I'm sure those wavelengths are attenuated quite a bit, but some are still emitted.

This may seem a bit counterintuitive, but the "color" and brightness of white LEDs has quite a bit to do with how much green they emit, as that's where the human eye is most sensitive.

Does an LED have a native color, by virtue of what it is?

Yes. An individual Light Emitting Diode is a speck of one compound. When electricity is applied electrons orbiting the atoms in the LED are excited into a higher-level orbital. When they fall back into their normal orbital they emit a photon of light. The wavelength of light for any given compound will be the same each time this happens. An individual LED emits only one wavelength. Manufacturers combine LEDs emitting different wavelengths to make fixtures emitting white light.

In colored strings of LED lights each lamp generally emits only one wavelength of photos.

Which is why a white LED is constructed similar to a fluorescent tube - the LED emits a wavelength that excites the phosphor painted over it, and that is what emits the visible light we see.

I don't know if there are any readily available chips yet that have a phosphor "tuned" for plants, but I sure wish there were.