In most of the eastern and midwest regions of the United States, rainfall is abundant throughout the year and plants thrive with water from this natural source. Not so in most of California, where dry summers require supplemental water for plants and lawns. Enter drip irrigation.IMG_1088

Before the advent of drip irrigation, most California landscapers installed irrigation sprayers. Water was delivered from a valve through underground PVC pipe to sprayers mounted on risers at intervals to water large areas of plant material (similar to lawn irrigation systems). Water was sprayed overhead and applied to the foliage of the plants, and also to areas between the plants, generating lots of weeds. Water was wasted, since areas without plant material were being regularly watered. It was a very inefficient way to apply water.

The Israelis developed drip irrigation in the late sixties into the seventies, and it rapidly became a widely popular water delivery system. Drip irrigation allows the application of water to the base of each plant only. Half inch black tubing is run from the valve, snaking throughout the garden among the plants and trees. We like to run the half inch drip tubing on top of the ground. If it is buried, it tends to get dirt inside where the fittings connect. In addition, it becomes very difficult to work on repairs and replacements. The emitters inevitably fail and need changing, and the connectors eventually work themselves loose. Also, any time a new plant is added to the garden, a new drip is required. So it’s nice to be able to easily access the half inch drip tubing, and if it’s buried it can be a challenge. The smaller quarter inch tubing or ‘spaghetti’ tubing is connected to the half-inch tubing and extended to each plant. An emitter is attached at the end of the spaghetti. A six-inch stake supports the emitter above ground to keep it from getting clogged with dirt.

Each plant has different water requirements, and this variation is accounted for by installing the appropriate size emitter or emitters to the plant…there are half, one and two gallon per hour emitters, and even larger ones for trees and mature shrubs. The emitters are pressure compensating, and the manufacturers recommend that the same brand and model of emitter be used throughout a single drip line. The length of time the drip system is run depends on climate, season and the maturity of the garden. When the garden is first installed and the plants are babies, shallow frequent watering is appropriate. Once the plants begin to mature and the root systems start to develop, a deeper less frequent irrigation is beneficial, driving the roots down, but allowing the plant to dry out in-between watering.

Drips and drip ‘sprayers’ can be used in other applications as well, such as for vegetable boxes. A separate drip valve and line of tubing and emitters should be used for a separate application.

Drip irrigation is an efficient, water-wise, low maintenance and economical water delivery system to plant material.