Q. I have a few orchids in my office (2 phalaenopsis, got 2 new Dendrobium) and was thinking about adding a grow light.
I have 2 phalaenopsis that have been doing ok in my office (temp generally 65 - 80). I just got 2 new Dendrobium. The office is not very sunny (blocked by buildings - maybe 1 hour of indirect sunlight at 4pm), but I do keep the fluorescent lights on all day. I was considering a desk lamp with a grow light bulb for the small cabinet they are on - do you think this is a good idea? Would full-spectrum or a red/blue bulb be better? Any other suggestions? (I can send pictures if that would help.) Thanks.
Phalaenopsis require temperatures of 60-65 degrees at night and 70-85 degrees during the day. They also require 1,000-1,500 foot candles of light for 16 hours a day (you can buy a small foot candle reader at a photo shop). Your florescent lights would have to be 12" or less above the plants and on a timer for optimum growth. For indoor culture hang (on adjustable chains) a combination of 40 watt tubes (one each) of warm white and cool white within 12 " of the plants. They also require 50-70% humidity which may be difficult to maintain in an office environment. You might try putting them by a window if possible. The dendrobiums are more demanding, need cooler temperatures and more light. Unless you are able to grow them at home where you can set up a light, humidity, etc. situation (often in a basement). Enjoy them if they are blooming and gift them to someone who has a more favorable environment when they stop blooming. If you would like more information contact the American Orchid Society which has local chapters and meetings.