Written by Nan Sterman
With water shortages from California to South Carolina, Arizona to New York City, even rainy Pennsylvania, what’s a garden lover to do? Adapt. We need to choose plants that survive on little more than rainfall. We need to improve our soils so they absorb and hold water. And we need to make our irrigation systems more efficient. Our task is to grow great gardens using as little water possible, applied as efficiently as possible.
Improving soils can be done with the addition of worm castings (Black Gold Worm Castings) to promote fungi, bacteria, and other beneficial microbes in the soil. Compost and mulch (Black Gold Garden Compost, Black Gold Soil Conditioner or Black Gold All Purpose Potting Soil) improve soil texture and provide the organic matter that feeds the microbes.
In terms of irrigation, it is time to replace fashioned overhead sprinklers with drip irrigation. With drip, nearly 100% of the water that goes into the garden goes into the soil where plant roots are. Overhead sprinklers, on the other hand, waste half of the water they put out. Some evaporates into the air, some is lost to over spray. Much of it simply ends up running off into the gutter. With so much waste, your out of pocket cost is twice what it should be. And, keep in mind that all that water running off your property carries fertilizers, pesticides, herbicides, and other toxic materials into our lakes, rivers, and oceans. The cost of this pollution is enormous.
Drip just makes sense. It delivers water where plants need it at their roots, in the ground. In fact, drip is so efficient that when water agencies set watering restrictions, gardens watered by drip irrigation are excluded.
How drip works
Drip releases water drip by drip. Where overhead irrigation delivers water on the scale of gallons per minute, drip releases water on the scale of gallons per hour. Even in gardens with heavy clay soils, water absorbs into the ground rather than running off into the gutter.
There are different types of drip technologies, many of which I’ve tested in my own garden. The hands-down winner is in-line drip irrigation. In-line drip (also called “dripperline”) comes from different manufacturers, but all basically operate the same way. In-line drip irrigation consists of a flexible plastic tube, roughly a half-inch diameter, with emitters installed permanently inside the tube. When you look at the tube, you see a hole every six or twelve or eighteen inches along its length. Run your finger along the tube over the hole and you can feel the thickness of the emitter.
In-line drip is different from laser drip, which is simply a tube with holes drilled in it. In-line emitter tubing releases a set amount of water from each emitter along its entire length. Emitter technology prevents roots from creeping in.
Some brands have check valves so that when the line turns off, water stays inside rather than running out and flooding the lowest point. In-line drip fits together with simple, push-in elbows, t’s, and other fittings. In most garden beds, lines are laid out in a grid, then covered over with a layer of mulch to help hold water in the soil. Because there are so few parts and pieces, these systems are very low maintenance. There are no tiny tubes to blow apart, no heads to twist off, break off, or get stepped on. Just remember to push lines aside before you dig in a bed.
There is some cost involved in the initial installation, but with drip irrigation, worm castings, and a nice thick layer of mulch, you’ll soon recover your costs in saved water and healthier plants.