No matter how much or how little room you have, a simple grow box can be customized to fit on a window sill or in a patio or kitchen corner. Grow boxes can be basic or elaborate, sustain an entire vegetable patch or a single crop. Start with a box that you can assemble in under an hour and enjoy for a season. Once you've had some success with the basic hydroponic system, you can expand next season to large grow boxes that will keep a whole vegetable garden in bloom, even if you go on vacation.
Set the bottom of a shallow plastic storage container or a 26-by-20-inch mortar box from the hardware store where you want your mini-garden. Use a box cutter or another knife to cut a 10- to 12-inch length of 4-inch diameter corrugated HDPE drain pipe in half lengthwise. Cut the half pipe into three sections that will fit snugly, crosswise, in the container box. Place them in the box with the open, cut sides down.
Mark a spot on the side of the box at a point just inside the top of the center section of pipe. Make a hole in the side of the grow box at this mark to serve as an overflow drain. If you over-water the box, the excess just drains out the side so the roots of your plants won't get soggy and rot.
Trace the open mouth of the empty water bottle on one side of the top curve of a half pipe. Use one of the half pipes on either end for this. Cut a hole where you marked the pipe so the bottle can sit, upside down, in the pipe. This is the water spout you use to fill the reservoir. Now cut the bottom off the water bottle so it becomes an open funnel.
Pack container mix---this is soil-free mix that is usually some combination of peat moss, Perlite and nutrient or fertilizer---around the three sections of pipe. The mix draws the water from the pipes like a wick to water the roots of the plants so tamp it down well. Once the pipes are securely embedded in the mix, fill the rest of the box with it, within an inch or two of the rim.
Fill the reservoir with water, using the water bottle spout. When water begins to spill out the overflow hole, you have saturated the mix. Let it settle for a while and then plant the seedlings you raised indoors or purchased at the local green market. Keep the grow box watered, make sure your plants are getting enough light or sun, and enjoy your mini-garden and eventual harvest.