Need some advice for growing under lights...

[naturepath]

Hello.

In my shelf, where I have my orchidarium, I also have a second - lower - level (under the terrarium), where I have a little light fixture (four t5 bulbs 24w).

The light level beyond this fixture on a 65 x 45 cm shelf tray is from 4500 lux (when using only two bulbs) to 8000-13000 lux (when using all four) - depending on the distance and position on the shelf.
The bulbs hang 45cm beyond the shelf.

Some masdas, I placed there to test this, got burned leaf tops, but some buds (leafs were 25 cm from the bulbs).

I now want to decide wether to use this culture place for little paphis or for others like angraecoid orchids. (I would prefer paphis...)

Temperature in the room is from 20 Grad Celcius (68 Fahrenheit) to 28 Grad Celcius (82 Fahrenheit) in summer day - depending on outside temps to 12 Grad Celcius (53 Fahrenheit) to 17 Grad Celcius (62 Fahrenheit) in winter night.

Could you please give me some advice, which genera I should choose?

Regards
Frank, germany

 

[NYEric]

Welcome to the forum from NYC. Some paphs like high light; some not so much. It depends on what you want to grow.

 

[naturepath]

My favorite paphs are niveum, concolor, bellatulum, fairrianum, callosum,
leucochilum, godefroyae, helenae, thaianum and their hybrids.

It also depends on their height and the size of their inflorescence, I think.

 

[NYEric]

There are a lot of forum members here who grow under lights, who can advise you. Not me. Of course no plant benefits from being so close to the lights that it burns up. Except for callosum, none of those you listed get that big/tall.

 

[naturepath]

Yes. Sorry, about callosum I meant the thai form which should be much smaller (thaiense?)

 

[NYEric]

Best way to find out if your set up works is to try a couple of plants. Good luck.

 

[Chicago Chad]

If you are burning masdies leaf tips; are you running a fan 24 hours a day and are you misting them?

If they are still burning at this distance and these temps, and the above mentioned is also being done, I would go Angreacums. Even better, Angreacums hung above paph seedlings, maybe in the Parvi and Brachi section.

I can keep an Angreacum dideri and and Aerangis citrata about 1" below a 2ft, 2 bulb HO T5 fixture without any burning. I also allowed them to get comfortable at lower levels and moved them up as they got larger.

I have never burnt a paph seedling (and I have some tiny ones) under lights over a distance of 15" with T5 bulbs. I also keep the humidity at 80%+/- with constant air movement.

Hope that helps.

 

[naoki]

My paphs are under T5HO (4' 54W x 4bulbs), and they grow/flower well (I grow most of the species you mentioned). When the leaves of tall paphs (multi florals) become within 10cm of the bulbs, the tips start to become a bit yellowish, but I keep the distance between the top leaves and the bulb about 20-35cm (approx. 8000-13000 lux). In the winter, I use 4 bulbs, but in the summer, I have to reduce it to 2-3bulbs (the grow tent starts to overheat), 14 hours/day. Similar to Chad, I also keep the RH high (ave 70% for me) with air movement.

 

[SlipperFan]

Welcome, Frank!

In my opinion, if you can adjust the height of you light fixture so that it doesn't burn Masdies, it should be fine for the Paphs you want. Of course, you can also turn off one or two of the bulbs if you can't adjust the height.

Otherwise, the amount of light your fixture give sounds good for bright light-loving orchids.

 

[naturepath]

Hey.

Thanks a lot for your posts and hints.

I don't have a ventilator on this installation. First, it was only a small "extension" for my windowsill and my orchidarium, which stands on the shelf above this. I placed a little aquarium (empty) and put some masies in it.
Because of the humidy in it I don't need to mist each day.

But some of the bigger masdies got burnt and the aquarium did not exploit the full space, the shelf tray gives.

So I decided to put a tray on this shelf part and fill it with water and an eggcrate to put some paphis on it.
It's like a small windowsill with artificial light...

Because it's the lower tray, the temperature is not as high, as on the real windowsill of mine and as in the orchidarium. Air movement ist good, I think. The shelf is open on four sides.

I already have some of the smaller paphis. But till now they're spreaded on the windowsill and in the orchidarium. I want to put them together on this shelf under the light fixture.

I think, I'll try it with 2 bulbs on for the beginning. When I realize, the plants need more light, it's just a "click" to give them more...

Regards
Frank

 

[Leo Schordje]

Hello and welcome to the forum.

Put a small fan in the vicinity of the lower shelf, with air movement, the plants will tolerate considerably more light. To get good blooming from Masdevallia, you really do need to give them light, so the Masdevallia would benefit from the fan on, which would allow you to leave 4 lamps on. More air movement, allows more light, this light creates more sugars for growth, more growth allows more flowers. You may have to adjust watering frequency, more air will dry out the plants quicker.

Paph bellatulum can take quite a bit of light if moved slowly into it. The rest of the brachys, godefroyae, leucochilum, niveum, concolor, all will tolerate fairly bright light, though they can get by in much lower light than bellatulum. I don't have experience with thaianum, I would worry about drying the plant out due to its small size. The parvi's like delenatii and armeniacum can take, and enjoy a surprising amount of bright light. I have had armeniacum in Cattley-Cymbidium-Vanda bright situations with no leaf burn. (good air movement though). Paph micranthum does not like quite as much direct sun, it does prefer more shade.

Summary. The lower shelf sounds very useable, just add air movement. I leave fans on 24 hrs / 7 days a week, inexpensive fans, you just need enough air movement that grassy leaves would waive a little. It does not need to be a hurricane.

One other benefit of air movement, that is not obvious, better root growth. Air moving across the top of the pots will mix into the potting mix, bringing oxygen to the roots. Plants in light gardens are healthier if we make sure there is air movement, even in small collections. By the way, I am a 100% under lights grower, have been growing under lights for many years.

Also, I really like the T-5 lamps. I have used all manner of lamps over the years, and they are my current favorite.

 

[naturepath]

Hello.

Thanks for your post and for the welcome

I will try this. For now, I put my leucochilus, two niveums, helenae and thaianum onto the shelf.

Ventilation... Hmmm, it's a working room and another venti, which "runs" 24h a day is not, what I wanted. I'll watch this some time, before I install one - if it is necessary. In my orchidarium, I have two ventis and they're running 3 times a day for 1h each. This is enough, I found out.
They are not silent...

Regards
Frank

 

[Linus_Cello]

Also, I really like the T-5 lamps. I have used all manner of lamps over the years, and they are my current favorite.

Have you tried LEDs yet? Thoughts on them? Maybe in the future when the technology settles down?

 

[Leo Schordje]

Have you tried LEDs yet? Thoughts on them? Maybe in the future when the technology settles down?

Don't really want to hijack this thread. I have tried LED's, and have observed others using them. As of my last trial, 3 years ago, they are not ready for prime time. Unsatisfactory results was my experience. They are improving, but until I see better results, I am not sold on them yet.

Last week I did look at an LED panel, that actually draws 400+ watts of electricity, designed to replace a 1200 Watt MH grow light. It was the first LED I ever saw that seemed bright enough, but it was expensive, very expensive, and 400 watts is still a high electric demand. It was WOW, bright. And the light color was not acceptable for a living space.

T-5's are nice in part because the color of the light is acceptable in a living room. Fairly natural color rendition.