Drip irrigation a smart watering tool
The gardener who can do a thorough job of watering with hose in hand is rare indeed.
Assuming that the hose spews out about 3 gallons per minute in a circle about 4 feet in diameter, I calculate that the gardener would have to stand immobile for more than two minutes before moving on to the next 4-foot-diameter circle of thirsty plants. Pretty boring, if you’ve got a whole garden to water.
A sprinkler is one solution. Even better is drip irrigation, a method of applying water to plants slowly and over an extended period of time.
One big benefit: It cuts water use by about 60 percent. That savings comes from less evaporation and less waste; water doesn’t go where there are no plants. Also, plants grow better because they’re never thirsty, and dry leaves mean less disease.
A primitive drip irrigation system could be cobbled together by running water through an old garden hose riddled with holes and with a plugged end. (The problem is less water would drip from the holes at the end.)
A drip irrigation system you purchase has water emitters engineered to offer consistent, specified output over wide changes in elevation and pressure. You can buy tubing with emitters at, say, 6, 12 or 18 inches apart. Or you can buy solid plastic tubing and punch in emitters wherever you want — ideal for widely spaced plants.
Emitters typically put out water at a specified, leisurely rate of onequarter gallon to 4 gallons per hour.
For a flower bed or closely spaced plants like carrots, tubing with emitters already installed wets the whole bed. Capillary attraction into small pores in the soil draws water sideways even as gravity pulls it down, so wet areas overlap.
Right at the hose spigot is the best part of a drip-irrigation system: the batteryoperated timer. It turns the water on and off, at about the rate plants are using water.
Of course, water use depends on weather and the plants, but a half hour of dripping per day is usually about right. That may seem like a lot, but remember, the water is just dripping. If a timer can turn the water on and off three times a day, set it for three 10-minute waterings; if six times a day, six 5-minute waterings.
The timer brings an important benefit: It saves time. Rather than standing frozen in your garden with a hose, you become free to do other things, like smelling the flowers.