Growing Lights - How many?

[butterfly_muse]

Evening everyone! We are moving at the end of the month, and the orchids will be moving from a shaded Southern exposure to a very shaded Northwest exposure. As you can imagine, I am going to need some lights because the natural light just won't do.

I am not sure how many lights to get, though I've been researching on Ray's site. How many do I need for 6 orchids? How high above the plant should they be? How long should they be on?

I also have two African violets and some kind of ivy, and a begonia. The ivy and begonia both need sun all day, so I need to do this for them as well.

I plan on putting the orchids near the window, probably on a shelf or something, as the window is oriented more west than it is north - it's just that there are a lot of trees outside. During winter, there won't be leaves to filter the light, but the days will be shorter..so I need to definitely supplement. Advice?

[Bill U.]

It kind of depends on what kind of space you have. Right now I grow a majority of my orchids under 25w CFL bulbs that are 6500K light temperature. I have two of these bulbs to cover my small growing space. For the phals- the are arranged about 1-1.5 feet away from the bulb (in a clamp spotlight reflector bought for $8 from Home Depot). Obviously, the higher the light requirements, the closer you can be. I would measure the light that they are getting now and try to match it in the new environment. I have been able to successfully grow/bloom roses and other full sun plants under these lights. So I think that this could be a starting point for your light setup...

[butterfly_muse]

Originally Posted by Bill U.

It kind of depends on what kind of space you have. Right now I grow a majority of my orchids under 25w CFL bulbs that are 6500K light temperature. I have two of these bulbs to cover my small growing space. For the phals- the are arranged about 1-1.5 feet away from the bulb (in a clamp spotlight reflector bought for $8 from Home Depot). Obviously, the higher the light requirements, the closer you can be. I would measure the light that they are getting now and try to match it in the new environment. I have been able to successfully grow/bloom roses and other full sun plants under these lights. So I think that this could be a starting point for your light setup...

How can I measure the light that they are under now? It varies a lot (today we had thunderstorms and sunshine...yesterday it rained all day, the day before that it was sunny and hot outside, etc). Right now I've got my plants on a baker's rack next to the window. I was planning on either keeping them on that or building a shelf as an extension of the sill and then suspending the lights over them. I haven't gotten it all worked out yet, just because we're not in the apartment. I can't do a lot because it is an apartment, so I can't go all commercial grower with giant lights and so forth, lol. How many lights do you have per how many orchids? Right now I only have phals, and I am trying to research but can only seem to get footcandle measurements and converting it to watts doesn't seem to be the correct kind of math (I suck at math, though, so)..

[Bill U.]

There are a couple of different ways that you could measure the light- there are some apps that are available on smart phones to use the camera to help measure light, or there are light meters that you could purchase (some of the best deals are on eBay). I would say to probably measure periodically if you are having cloudy days or try to measure a couple of times a day during sunny days to get an average light strength that your 'chids are receiving and then you can use that to get a target light intensity for under your lights.

I hear you on being short of space in a room- I'm currently growing in a dorm room. Right now I only have 2 lights- one for 2 roses that are both in 6" pots and are ~1' wide, and then the other light I have a tropical hibiscus, a phrag besseae, a phal, 2 chrysanthemums, and a few seed trays. If you plan your lighting correctly, you can fit quite a lot of plants under 1 light- a lot of my strategy is angling the light to maximize the coverage area and then placing high-light plants closer and the lower-light plants farther. I also have 3 phals growing on a shaded-west windowsill.

As far as I know, there is not a very good conversion of footcandles to watts (or vice-versa). But I would be inclined to say that with the 25watts you should be able to simulate almost direct sun up to a distance of about 6-8 inches. The conversion really doesn't do much good until it takes into account the spacing between the light and the plant. A light that is 1 watt at 1" from the plant could be stronger than a 25 watt at 15" from the plant... (maybe a slight exaggeration, but the idea is there).

[clusty]

You could also use an SLR camera to measure foot candles.
Light Intensity Measurement

[butterfly_muse]

Since I have all Phals, would it be a better idea for me to put the full-sun needing plants like..maybe above the phals to create that kind of shading/indirect scenario? I burned two of my phals in direct sunshine out on my patio, so now I am paranoid haha.

[Bill U.]

That may be a good idea for you to do. That's what I do with my hibiscus to shade my phal that's under lights.

[butterfly_muse]

Originally Posted by Bill U.

That may be a good idea for you to do. That's what I do with my hibiscus to shade my phal that's under lights.

Have you been able to get your orchids to successfully spike or grow new leaves and stuff? I am so worried about giving them too much/not enough light, lol. It's driving me batty.

[Bill U.]

I have gotten new leaves on every single one of my phals in addition to new roots. I have not rebloomed any of my phals, but the one that I have received in spike has been in bloom for over 3 months (in addition to putting out a new leaf and crazy amounts of roots).

[quiltergal]

I would recommend reading through this forum. Growing Under Lights - Orchid Board - Most Complete Orchid Forum on the web ! There is a lot of very good information there that should answer most of your questions.