Watering Soil-Beds or Grow-Boxes with pre-drilled 3/4″ PVC pipe is fast, works better than a hose or sprinkling, and saves water. Pictorial instructions are on the Garden Master CD, The Mittleider Gardening Course, Grow-Bed Gardening, Let’s Grow Tomatoes, and Gardening By The Foot. First, start with a level bed or box – that’s essential! Here are the basics.
Plumb water to the head of each bed or box, with a simple female-threaded 3/4” ball valve 4-6” above the soil surface, to control the flow.
Make 30’ lengths (or your bed length, if shorter) of 3/4” Schedule-200 pipe. On the end of each pipe, make marks dividing the circle into 4 equal parts. Two adjacent marks are at 90 degrees. Now make a mark between those two, and you have the starting points for 3 straight lines down the length of the pipe that are 45 degrees apart.
Take a piece of 2 X 4 – 6″ long and notch one side of it so that a 3/4″ PVC pipe fits snugly. Drill a hole from the top to the center of this notch the size of a pencil. Insert a sharpened pencil, and as one person holds the pipe from moving, another person starts at one of the three marks on the end
of the pipe and makes a straight line the length of the pipe. Turn the pipe to the next mark and repeat. Then repeat a third time.
Next, take a measuring tape at least as long as your pipe, place it alongside the pipe and draw a line every 4″ across the 3 lengthwise lines already drawn on the pipe.
Insert a #57 drill bit (that’s very small – .042″, and is found at a hobby shop) into a hand drill and drill 3 holes every 4″ the length of the pipe – on the points where the lines cross.
Attach male threaded ends on both ends of your pipe. On the far end, place a threaded end-cap, and attach the front-end to the ball valve plumbed to your water source.
Place the pipe in the center of your Soil-Beds or Grow-Boxes, on 4 small 2 X 4 blocks equally spaced along the length of the bed. Each block should have two nails in the top center spaced 1″ apart, to keep the pipe from falling off.
With the holes at 45 degrees and the pipe 3 1/2″ above the soil surface, the water will quickly fill the 12″ planting area the entire length of a level bed or box, and water all plants equally.