Doing Drip Irrigation Right

If you want to save water (and money) with drip irrigation, it all comes down to selecting the right design for your landscape, installing it properly and scheduling it correctly.

Drip irrigation saves water, right? It’s a question I hear quite often and the answer actually depends on your landscape design, type of drip irrigation and, most importantly, how it is scheduled.

How efficient your drip irrigation is relies on proper installation and how it’s scheduled. Of course, selecting the right design for your landscape is the first step. Drip irrigation comes in two designs: point source and inline tubes.


irrigation in garden

Point source is the old-fashioned style of drip irrigation with many small tubes coming from a communal head or a long length of black tubing. This form of drip is great for widely spaced plants that are quickly established. Point source drip irrigation may be removed after 90-120 days and the plants are on natural rainfall only.

Scheduling of point source is fairly simple. The emitters on the end of the “spaghetti’ tubes come in rates of half-gallon per hour, 1 gallon per hour and 2 gallons per hour. As I indicated last week, horticulturalists and foresters apply water in inches per hour. One inch of water is .62 gallons so the half-gallon per hour emitter is appropriate for once a week watering. Remember, all plants, with the exception of vegetables and seasonal color, prefer once a week to once a month watering.

Initially, place the emitters next to the plant. Later, move the emitter away from the plant as the roots grow. This is one great advantage to point source drip irrigation: it can be moved to follow plant roots.


Inline tubes, on the other hand, are great because they provide a uniform amount over a wider area and are inconspicuous. Inline tubes are good for landscape designs incorporating a lot of plants in close proximity and can be spaced 2 or even 3 feet apart.

Scheduling the run time with inline tubes drip irrigation is a little more complicated than point source. Like the previous article, there is some math involved.

You need to know the emitter rate, spacing between tubes, and spacing between emitters along the tube. We recommend specifications that are designed for South Texas plants and to conserve water. These are .6 gallons per hour (emitter rate), 18 inches (between tubes) and 18 inches (between emitters along the tube). Here is the formula:


Picture of Mark Peterson
Mark Peterson
Mark A. Peterson was a conservation project coordinator for San Antonio Water System before retiring. With over 30 years of experience as an urban forester and arborist, Mark is probably the only person you know who actually prunes trees for fun. When not expounding on the benefits of trees and limited lawns, you're likely to find him hiking San Antonio's wilderness parks or expounding on the virtues of geography and history to his friends.
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