Growing taller catts under lights?

[dshallpost]

Wondering if taller cattleyas can be grown under lights (with no window light) since the bottom of the plant will be much further from the light than the top.

In an enclosed space I have three LED fixtures with 4 bulbs each. They are full spectrum. (The LED bulbs are the same size as T5 and fit into a T5 type fixture) Near the lights the output is approximately 1800FC. But of course the light drops fast as you move further away. That's why I'm wondering if this set up will work for taller plants.

(My temps range from mid 60's night to about 81 day, and humidity is about 65%. Fans running 24/7). Currently on a 16 hour day.

One of the three fixtures has seedlings and small plants, one has compact plants like Potinaras, a Lou Sneary, a Vanda Cristata.

I was planning to have taller cattleyas under the third fixture. I have one taller plant, an LC Roebling Beachview, which seems to be doing alright, new roots, a new growth starting, but has not bloomed yet (have had it about 3 months) But I am wondering if it can really be getting enough light. Would like to know if anyone is growing standard size catts or other taller high light plants under lights (with no supplemental window light).

The other thought was to keep only the larger catts outside for the summer and under lights for the other seasons.

Would welcome input on this . . . .

[Subrosa]

I grow a Cymbidium Little Black Sambo that including pot is nearly 4' tall under lights when it's too cold for it outside. Until I moved last year it received no supplemental sunlight in the room I grew it in. You can grow any plant indoors under lights if you can give it the space it needs, get the right light and pay the electric to run it.

[Ray]

If the light source is far enough away from the plant, the relative intensity is fairly even, top-to-bottom. If you merely "guesstimate" using the inverse-square rule, you can see that:

Using the example of a plant that's a foot tall, with the top two feet from the light, if the light intensity is "X" @ 1', it's 1/4X @ 2', and 1/9X @ 3', meaning it is about 65% less intense at the bottom.

Move that plant to 6 feet from the lamp, and the intensity at the top is 1/36X and 1/49X at the bottom, a 26% reduction.

Of course, that means you're going to have to have a lot more wattage!

[Leafmite]

How tall? I grew some Cattleyas that were around 24 inches under fluorescent T5HO lights without any trouble (except the flowers got too close to the lights and were damaged). If you have different heights, you can raise the height of the smaller orchids by putting something under them.
Some of my tropical plants are around three feet and they did suffer (they are recovering nicely outside). They will be getting supplemental light from a window.

[dshallpost]

Thanks all for the input. I will go ahead then and try it out!

[Ray]

Also, consider shadowing: if your light source is only directly overhead, the plant will create a shadow with its own leaves. If, on the other hand, it's spread out, hitting the plant from multiple directions, its less of an issue.

[dounoharm]

very interesting! in the same vein, I have heard that by gelding colts early (before 6 months), they could grow taller…..so, as I had a purebred Connemara pony colt which was getting close to 7 months old, and a 1/4 Thoroughbred, and 3/4 Connemara colt, half brother of the first colt, which was 5 months old....I figured to have the vet do both boys at the same time....now, goblin, the purebred, grew to right at 14.2 hands tall....but the younger boy, owlsly, whose mom was half TB and half Connemara, bred to my Connemara stud, grew to be 15.3 hands! so, on the basis of one experiment, I guess that gelding early did indeed aid in more growth with owlsly! marvelous!....just a sidebar on basing any experiment on one example....lmao

[dshallpost]

Just following up -- I bought two larger cattleyas -- a Makai Louise and a LC Roebling Beechview. They are about 24 inches tall when blooming. I have had them since last summer and they just finished blooming. I have four fixtures with the lights at varying distances from the trays, to accommodate different heights. So, you can definitely flower larger cattleyas under lights.