It ain't rocket science, only simple irrigation installation
Last updated 6/1/2007 at Noon
Let’s focus on irrigation. Once you have installed it, it’s freeing. You become in control. You can even automate, which allows weekend or even week-long trips even in the hottest weather.
Last time we talked about putting half-inch black poly hose in a four-inch-deep furrow under the mulch and compost on the garden bed. Put two in each three-foot-wide garden bed, eight inches from the edge of the bed (see diagram). I use pressure-compensating (one gallon per hour) drip emitters. I put one of these into the hose every foot in as straight a line as possible. This variety of drippers costs a bit more but lasts a lot longer without plugging as easily. They are available at all local irrigation companies.
Now it is time to attach this poly hose to a header system for water delivery. You can buy black half-inch inserts that use PVC glue to attach them to half-inch PVC pipe fittings. Wait until the PVC glue on the half-inch fittings is good and dry (a few hours) and then insert the half-inch poly hose in them. Do not glue the black poly hose into this fitting (called a compression coupling); it is barbed so the poly hose cannot back out. Insert the poly hose onto the compression coupling, three-quarters of an inch.
Then take the half-inch PVC fitting that this is attached to and, with a reducer bushing (a PVC fitting that allows two different sizes of pipe to adapt together), glue it into a three-quarter-inch tee (this fitting is shaped like a T). Glue these two three-quarter-inch tees to three-quarter-inch PVC pipe so they evenly line up on the bed in the furrows you made. At one end of this three-quarter-inch PVC pipe, glue on a slip cap. On the other end, near a water source, glue a threaded male adaptor. This male adaptor will screw in to a 10-PSI pressure reducer that goes to a female hose connector. Bring a hose from the nearest faucet and you are almost ready to go.
Local irrigation companies are usually willing to help you design this kind of a system if my explanation is too complicated or too hard to understand. You will want to buy parts from them, as they have the best selections available and are a great resource.
Let all the PVC glue dry a few hours, then turn the water on. As the other end of the black poly hose is still open, this will flush out any dirt that might have collected in the pipes and emitters during construction. Do not turn the water on super-high, only medium, and watch to see that it runs clean before turning it off. Then, take the open ends of the poly hose, fold them over and slip a one-inch PVC coupling over the fold to keep it closed. It can be removed at any time to clean out the system.
You are ready to go now. Run it until the ground is soaked (if dry this could be 12 hours or more). Make sure all the emitters are working and replace the ones that are plugged. After that, keep the soil moist but not wet. By using the one-gallon-per-hour emitter, the water enters the soil slowly and penetrates deeply. Since there is very little runoff, this is a good year-round water-conserving irrigation system – good for your budget and the environment and great for your fabulous gardens.