Foot Candle

[chrisa]

Hello everyone,
I have read just about every orchid post/article that exists, and multiple google searches, but the one questions regarding foot candle requirements for orchids has not been answered.

The question is simple, if an orchid requires (e.g.) 1000 foot candle of light, does that mean:
1. That is the peak amount of light it requires at any one instance in time, or
2. Does that mean that throughout the day the plant should receive that amount of foot candle hours (e.g. 200 ft.cd. per per hour for five hours)?

Food candles are a measurement of light in one instance, but it does not explain if it is an average amount of light throughout the day.

Can someone explain this to me?

[Magnus A]

This is a very diffuse thing!

When talking about artificial light most people report instant light measured by a light meter.
When you se a report about the light in the natural habitat, you very often see very high number, those most often represent maximum amount of light at noon. When the sun is strongest.
The light during the rest of the day can be much lover. As for example, in most tropical rain forests it rains in the afternoon.

What can be said is that for artificial light it is the total amount of light that is interesting. Lover light levels can often be compensated with longer time, to a certain degree. Though there are orchid that really need high light intensities to flower!

/Magnus

[Ted Davis]

Chrisa...The 1,000fc measurement is the minimum requirement for a particular orchid, etc. to, for lack of a better term, 'survive'...Magnus hit it right regarding light intensity. It is at its peak during the mid day as opposed to early morning or late afternoon. It is very difficult to maintain a consistant light source without elaborate shading facilities. Don't freak. You must consider where you are keeping your plants, ie, windows, outdoors, greenhouse etc. Most orchids thrive best in somewhat shaded areas. Vandas like sunshine most of the day. As long as you have shde ambient light, your orchids will do just fine. I hope this helps. I am in Thailand where the sun is pretty intense most of the year. I keep all of mine in a partialy shaded area...and I have over 260 orchids...All the best, Ted.