Changes which occurred due to change in light.

[Nancy]

I thought this might be an interesting question. I added supplemental lighting to a north window and noticed several thing occurring. One is that new growths on my cattleyas turned bright red. Another thing I noticed is that flowers don't last as long on a plant or blast. I also noted that my new growths are smaller than the previous growths. I think probably I increased the light too much. Has anyone had any really positive changes, such as multiple growths breaking or more flowers? I'd love to hear your experiences with artificial light.

[tom499]

Since using grow lights I have seen more spikes forming, but this does fit with the flowering seasons so I cant really use it to support that.

I have seen more red colouration in some orchids, and my Nepenthes have produced smaller leaves. Leaves are turned a lighter green colour in general. I guess this is down to plants not needing such big leaves and so much chlorophyll due to the increased light intensity.

[mayres]

It can be a challenge to come up with the correct amount of light for your plants, especially when you are trying to light many different genera under the same fixture(s) - watching the amount of red can be an excellent guage for some. I have a a few cattleya and dendrobium types that have been over exposed to the point that their leaves are nearly entirely red - not good. Other plants like Tom mentioned they just seem to get paler and paler till they yellow and fall off - so yes - good luck finding that happy medium with yours. BTW - when using shop lights (T8's) for two years it was impossible to over light anything - the majority of my plants were underlit. Now with T5's I'm going through a whole new learning curve. What kind of lighting are you using Nancy?

[Nancy]

I'm using small flourescent bulbs in individual reflector sockets. They seem very bright. I have one plant directly under one of the lights that seems happy. That's Cattleytonia Keith Roth 'Stephen Fouraker' (subvariety Robson). I've got a new growth coming on this plant and massive root growth. It's hard to imagine that the plants can be getting too much light. Those new growths just look too red to me. Oh, I have three of these bulbs shining over a three feet by two feet window seat and window sill.

[tom499]

Alot of plants do enjoy good light as long the leaves dont get too hot. Mine have been mostly trouble free because I introduced the lights slowly bringing to the distance they are at now. This allows the plants to adapt better, so less chance of scorching.

[mayres]

Can you post a picture of your plants that you believe are too red? Might not be a bad thing at all? I've noticed that plants that produce pink or magenta/purple flowers especially tend to also show reddish foliage when the light output is nearing the max. What wattage on your fluorescents and how many inches down to your plants?

[kmarch]

Given the light set up you've described and given that some of your plants, e.g. the Keith Roth, are really doing well, I suspect there might be another reason for the bud blast and weak growths. I agree with Mike that red pigmentation on cattleya growths can be perfectly normal. Bud blast can also be "normal" (although certainly not desirable, especially if there are some change in conditions. Premature flower fading, bud blast, and weak new growths can all be symptoms of insect infestation, especially aphids or other sucking insects like scale. Scale can be deceptive because it can hide under the rhizome and in the mix on the roots and you may not notice them as they deplete your plants energy. Consider unpotting your ailing plant, examint the roots and underside fo the plant.

Let us know that you find and if you have questions.

Originally Posted by Nancy

Cattleytonia Keith Roth 'Stephen Fouraker' (subvariety Robson).

On a different related topic, orchid hybrids don't have varieties and subvarieties. These are found only in species. I'm not sure where the subv. Robson came from but it's not part fo the name.