How close do fluorescent lights have to be to indoor propagation trays to be effective? I would like to use the ceiling lights I have in the basement. If I were to set up a couple of sawhorses with propagation mats, do you think I could get by with the ceiling lights, or will I have to lower them to within a foot or so of the seeds?
C wrote in news:pan.2004.01.18.17.35.33.470059 @yahoo.com:
Everything I've seen says you should put them really close like within inches, but my pet theory is you can build a hugh reflector (or two) from leftover AOL discs and just use the ceiling light.
Regular fluorescent lights need to be within a couple of inches of most plants you might start. say, tomatoes. I'd give them 12 or 14 hours a day too. If they don't get enough light they'll get tall reaching for the light but be very weak and skinny. Another problem you'll run into is that as the plants grow taller and you raise the light to give them room the lower part of the plant won't get enough light, so you don't want them growing too tall under the fluorescent. It's best to transfer them to a cold frame and sunlight as soon as you can. Plants started under fluorescent must be hardened off carefully when placed outside or the shock of sunlight will do them in. I've started thousands of them this way but I'm now very happy to have a metal halide light. It can be placed well above them and still get plenty of light to the whole plant. It also allows for a very brief hardening off period without even messing with a cold frame.
That's what I thought. Now, if only I can remember where I put that bag of AOL CD's!
I will vary depending on what you are growing. I have a flat of parsley seeds germinating under fluorescent lights. The tubes are about 2" from the soil surface. Hang your lights on chains for ease of adjustment--much easier than trying to adjust the pots and trays.
I start my plants with fluorescents every year. When I first tried this (maybe fifteen years ago) I kept the lights 6-8 inches above the plants. All those plants came up but quickly got tall and leggy - not good. The second year I did the same thing with the lights but ran a fan on the plants to help 'harden' them up. They all just fell over and still became quite leggy. The next year I wisened up and put the fluorescents right on top of the plants - within an inch. Initially I was afraid the heat from the bulbs would hurt the plants but that's not the case at all. I now use fluorescent 'grow' lamps which more closely mimic the full spectrum of the sun. I also still use an oscillating fan to toughen up the plants about two weeks before outside planting time. Just make sure to properly 'harden off' the plants before you set them out in the garden. Good luck.
NRJ
Thanks.
I have GE Chroma 50 lamps. Although these are not gro-lites, they do approximate midday color temperature. I would guess these will work just fine. They are also considerably less expensive than the lamps being sold as gro-lites.
Thanks for the info on how to use flourescent loghts it really made a didderence in my garden. Tamme
Thanks for the info on how to use flourescent lights it really made a difference in my garden. Tamme
As close as possible. Maybe even closer. Not touching.
When I used lights for starting in the basement, I used two shop lights mounted right next to each other. I could get 4 flats under the pair of lights. I would set the flats on a stack of newspaper to place them as close as I could to the lights. As the plants grow, you just take out sections of newspaper to lower the flat. The newspaper absorbs spilled water. The fluorescent bulbs are not as hot as incandescent, but they do generate some heat. If a plant grows into the lamps, you have a half a day to a day to get them out before they start burning (actually just drying out, not actually catching on fire).
Some plants always got leggy anyway. I find that sunlight is far and away the best way to start plants. Much better than lights (although I haven't tried the high intensity greenhouse lamps). A couple of trial runs will tell you which plants can be done under lights and which need real sunlight (depends partly on where you live).
Another problem with starting plants in the basement is damping off. This is caused by high humidity at the point where the stem comes out of the soil. The humidity encourages growth of funguses that kill the plant. If you place a fan in the room so that air circulates, this reduces the problem significantly. You don't have to blow the air onto the plants, just keep the air moving. Leave the fan on all the time.
For tomatoes, a common practice is "brushing" the plants. This is basically moving the plants around by running a brush over them, first one direction, then another. The mechanical stimulation of the stems strengthens them and makes them thicker, so that they will withstand wind better when they are transplanted outdoors. Once or twice a day. I have around 50 flats of tomato plants. I use a leaf blower on them to strengthen them. A smaller quantity of plants can be done easily by hand.
Thanks for tip about basement germination and damping off. Unfortunately, I do not have a southern exposure on my house. The building faces east/west with only a small bathroom window on the south. Poor construction design and lack of foresight by the builder, I know.
My idea was to put flats on propagation mats under fluorescent tubes in the basement. Now I may consider starting seeds using whatever light comes in from the west. At least the plants would get some sunlight.
I would still use the mats.
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