I don’t want to spend too much money on lamps, and the space between the window, the plants and the curtains is very small, so i don’t think it would be wise to put some 100W of heat right next to the curtain. I think these are okay: 10 euro’s for a 15 Watt CFL (the site claims it gives light as a 75 Watt incandescent).

http://www2.conrad.nl/goto.php?artikel=610325

and the manual (in german  )-: ) is here:

http://www.produktinfo.conrad.com/datenblaetter/600000-624999/610325-da-01-ml-MegamanErsatzPflanzenlampe_ESL_15W_de_en.pdf

There’s a graph of the spectrum, which looks like it’s intende for plants, but i’m not sure if it’s not just a waste of money because they’re either to weak, or simply too cheap… Anyone?

This is a simple DIY way to make a reflector for a compact florescent (CFL) bulb.

There are many situations where you are lighting a plant and half the light coming from the bulb is going out your window, on the floor, or into you living room. A lot of this wasted light can be redirected back at the plant with a simple reflector.  With CFL’s the best light comes out the side of the coil, therefore a standard shop light reflector is not very affective. Fortunately it is possible to make a  effective CF reflector in under 10 min.

You will need:

1- 16oz beer can (12oz work, but not as well for bulbs over 15 watts)

1- CF bulb, I used a 26watt one

1- Clamp light (this will work for other fixtures too)

tools:

needle-nose pliers

tin snips or scissors you don’t care about

pocket knife

Step 1-

Take apart clamp light. With out a bulb in it (and not plugged in!!!!) twist the reflector off. It is threaded into the plastic, and it should come off in 3 to 5 revolutions. Next loosen the wing-nut until everything falls apart. You should now have something like in this pic:

Step 2-

Cut up your can. I started by poking a hole with a pocket knife, then attacked it with scissors. First I cut a strait line the length of the can starting and ending just before the metal starts to curve in. Next I cut off the top of the can. On the bottom of the can I cut a slit almost half way around on each side, leaving about 1/2in. on the opposite side as the slit.

It should now look something like this:

Step 3-

Cut a hole in the bottom of the can that the light fixture will fit into.  I did this by poking a hole with a knife and then pulling back the metal with pliers.  Notice in the picture that the hole is not centered, instead it is located closer to the side which was cut. This will give more room for the bulb.

It is also important that the hole is not much larger than the plastic fixture. When opening the hole, the extra metal should not be removed, as it is necessary for the next step.

Step 4-

Put the clamp light back together, with the new reflector.

Slip the new reflector over the plastic fixture, and bend the excess metal so that is touches the plasic. Then reconnect the bracket that connects the clamp to the fixture so that it compresses on these flaps of metal. This is what will hold the reflector to the fixture.

If you are not using a clamp light this connection could be made with a hose clamp, or my favorite thing; annealed steel  wire.

Step 5-

Fold the cut edges of the reflector.

Be careful with this step, it is sharp! Gloves may be a good idea, though it’s not as bad as most sheet metal, as aluminum is rather soft.

I bent a little under 1/2 in. of the edge over. This makes the reflector much stiffer, allowing you to bend it to the form you want.

At this point the reflector could be painted white, or better yet coated with silver Mylar. This can easily be attached with spray adhesive. Just cut the Mylar to size, spray, and stick it (read the directions on you spray adhesive)

Step 6-

Test it, and tweak it.

Bend the reflector so that it shines the way that is most useful for you.

For larger bulbs, like this 68watt CFL, a coffee can can be used.

You can grow edible plants with 100 or 150 watt CFL bulbs. Even fruiting plants. I have done it successfully in several windowfarm systems. You must use CFLs with the proper color spectrum. The “daylight” bulbs you get at Home Depot in the blue package work. Arrange your plants so they are no more than a few inches from the light. You will need to move them frequently or they will grow into the light and singe themselves. I highly recommend putting them in a window so they are also getting at least some indirect natural light because I highly doubt that these CFLs really provide the complete spectrum of light that plants need. You can put them on a timer so that they are only on a few hours during the day to supplement natural light. This keeps them from blinding you at night.

Until plants reach the adult phase, they require more light. I generally supplemented seedlings light for 18 hours per day. Then, once they reached maturity, I decreased to 12 hours.

This is my “work” farm.  I started it last week and already have two sprouts in it — rosemary and violas.  There is a desk lamp shining a CFL on it (on a 12 hour timer).

We have a second one (which was the first) here at home but I can’t find the photos of it right now (and am a bit too lazy to take a new one.

I saw a post about the window farms on Gothamist and just HAD to try it.  Got to say, it’s fun!  Folks walk into my office and are incredibly curious about what this curious structure is.

My husband and I are designing a larger farm for our living room window and will probably build it over the winter break (we are teachers).  Our major problem is getting the soda bottles since we use the SodaStream carbonator fr our soda needs and don’t drink bottled water.