Growing Cattleyas under PAR38 - Page 2 - Orchid Board

Mor · #11 02-13-2015, 08:31 AM

Another photo

terryros · #12 02-13-2015, 08:40 AM

I think it is telling you that you are at the maximum of the light the plant can handle. There is much more collimated light with LED lights than the diffuse light you get with almost anything else, including sunlight entering a green house. Standard measures from various light meters don't mean the same thing with LEDs. With these ALT PAR38 bulbs, I think you want the tops of the leaves of your Catts at least 9 inches away. At this height you will be getting a circle of illumination with a diameter of about 22 inches. However, depending on the species/hybrid you may find that you need less light than this. Watching the leaves as you are is a good way to determine whether you need less or more light.

ALToronto · #13 02-13-2015, 08:49 AM

Completely normal. It's getting plenty of light, and the purple coloration (anthocyanin) is a normal response. It's like suntan on people - if you shade a portion of a leaf, you will have a light green spot the size and shape of the shaded portion.

In the wild, some cattleyas become much more purple than yours.

Subrosa · #14 02-13-2015, 09:05 AM

Quote:

Originally Posted by Mor

so everything seems to be fine with the ALT Par38 bulb except of my purple Catt. Her leaves turned purple! And I mean that all the leaves turned really purple! It's not only the tips.. I attached a photo. Is it bad?

Is anyone think that high level of artificial light can harm low light growers? They can't burn in any way because of the leaves temperatures, right?

Thanks!!
Mor

That's a tan, not a burn.

Mor · #15 02-13-2015, 09:15 AM

Thank you all for answering.

Do you think that low light growers (such as Paphs or Phals) can get harmed or burned by high levels of artificial lights? I mean that if next to my taned Catt. I'll grow a Paph, under my Par38 - can my Paph get dammeged? (Sorry if I'm not clear enough - my English is not as good as my Hebrew..)

Subrosa · #16 02-13-2015, 09:32 AM

No doubt that you can overlight a low light orchid with artificial lighting. But depending upon how the light is positioned you might be able to grow a Phal directly next to the Catt without burning it. The edges of the lighted area will receive less light.

ALToronto · #17 02-13-2015, 09:42 AM

It depends on the phal. Some have naturally purple leaves and can tolerate more light. It's difficult to overdo artificial light - it's never as bright as sunshine. Burning from heat is a bigger risk.

I have over 60 phal seedlings growing on a sunny windowsill, and they do ok.

DelawareJim · #18 02-13-2015, 06:58 PM

Im growing 6 Paphs about 8 inches under a 24 inch Build My LED Start-Max strip that have been growing very well. My Winston Churchill is in bloom and the colour intensity is the best I've ever seen. LED Grow Lights | Best Plant Growth Light | High Power Start-Max Spectrum Light Bar

Cheers.
Jim

gngrhill · #19 02-14-2015, 12:24 AM

You might have to increase the light intensity more slowly if your catt is not used to that much light.

Gravelsack · #20 02-14-2015, 01:18 AM

Not exactly the greatest picture, but I thought I'd show what happened when I put my C. luteola about 4" away from my Maxspect Razor. You can see by the little hemisphere shaped mark on the smaller leaf that the discoloration only occurred right where the light was hitting it. The same is true for the marks on the other leaves as well.

I have since moved it down away from the light.