I'm growing a number of citrus trees under lights this winter and they are doing great. I'm using 1000 watt HID metal halide lights. I try to keep them at least 4 feet away from the lights. HID, unlike fluorescent bulbs generate quite a bit of heat and cannot be placed close to the plants. I have some other plants under fluorescent tubes but no citrus. The plants can pretty much touch a fluorescent light without any damage.
Karyn

Thanks Karyn. Flourescents are what I have, and I want to know if they will suffice

I've kept my citrus trees in a greenhouse with supplemental fluorescent (regular, not HO) lighting over the past few years. They did alright but I'm having MUCH better results with the HID lights even though they aren't in the GH this year. Here's a link that explains the different types of grow lights. HTH
http://www.littlegreenhouse.com/guide3.shtml

Karyn

I also have a 1000-watt metal halide setup. My citrus are all starting to bloom again and put out new growth! But that may be because I let them dry out while away for over a week last month.

Kinda depends on how large your plant/plants are. I would think with fluorescents, you would need the bulbs as close to the plants as possible (nearly touching), use multiple lamps -- maybe four units (each with two bulbs like shop lights), and keep them on for at least 14 hours. Whether that's enough light for them to bloom I don't know, but it should be sufficent to keep them alive. Supplemental light from a window would also help.

But I'm sure there are others out there with more xperience.

That is the setup I have Dave. I have a fixture w. four flourescents in it. I am not necessarily looking for them to bloom inside, but rathwer just over winter them in the house, and move them outside to my unheated hobbyhouse when the weather cooperates.

Sounds like it should work. The problem is when the plants get taller, the lower leaves are shaded or are too far away from the fluorescents (light levels drop exponentially as distance from the bulb increases). Then you're getting good light to the tops of the plants, but not so good to the lower portions of the plants. See how your system works. You could always install another unit sort of on its side to illuminate the lower part of the plants, then rotate your plants every week or so. Maybe that's too much work?