DIY Drip Irrigation

Timers: A timer allows you to go on vacation knowing that your landscape and patio plants are going to be watered appropriately. Timers are wind-up, battery-powered, AC powered or solar powered. They handle one zone (wind-up) or up to 12 zones. All powered timers offer similar functions. When first powered up, you set the current time and day of the week. Next you choose which zone you are setting up (for multi-zone timers). Then, for each zone, you set the duration, days to irrigate, and a start time for each irrigation (up to four start times). Multiple start times are useful for high volume watering using shrubblers, micro-jets, mini-sprinklers, or sprayers. These devices are designed to cover areas not specific plants and can lead to run-off. You can avoid run-off by watering for multiple short intervals. Galcon LCD timers have worked well for my needs.

The type of soil in your garden will determine the irrigation schedule and emitter choice. Clay soil holds more water, is slow to absorb water, and is slow to release water. For this type of soil use 0.5 GPH emitters spaced farther apart. Loam, which is the optimal soil type, is very porous and retains moisture. Use 0.5 – 1 GPH emitters. Sandy soils are extremely porous and allow quick water flow. Use 1 – 2 GPH emitters closely spaced and water more frequently for shorter periods.

Filters: Because drip irrigation emitters contain very small channels, they are susceptible to clogging. It’s important to always include a filter after the timer. Garden filters come with hose threads or pipe threads. Screen filters remove sediment and debris that can clog a drip system. Filters are rated by filtering capability. The common terms used are mesh, the number of wires per inch and micron, the maximum particle size that can pass through the screen. Home garden screen filters are commonly used for small to medium size irrigation systems with a relatively clean water supply. Common mesh sizes are 50, 100, 150, and 200. I use Irritec hose thread Y filters with 200 mesh.

Most municipal water systems supply water at 40 – 60 psi. This is too high for drip irrigation systems. Pressure regulators come with hose threads or pipe threads. Senninger Garden Regulators are ideal for low-volume drip systems. They will regulate pressure from 10 psi to 40 psi. I use 30 psi regulators in my gardens.

In the old days (back in the 1970s) I assembled drip systems using Raindrip compression fittings. These could be bought at hardware stores or nursery centers. They come in straight couplers, elbows, tees, and hose starts. They are black plastic cylinders with compression elements at the open ends. You push the ½” polypropylene tubing into the open end wiggling it around and jacking it back and forth to force it into the fitting. Once in, it doesn’t leak. But like the Hotel California, once you check in, you can never leave. One day I was watching farm hands installing a field for strawberries near where I lived then in Carlsbad, CA. The tractor and implement produced flat-topped raised beds across the field. Then the workers laid down T-tape (also called drip tape). Then they covered the raised beds with black plastic. They made slits in the plastic and planted strawberry plants in the raise beds. The drip irrigation system was in situ. Dripworks carries the latest generation of tape technology from Toro called Aqua-Traxx drip tape. The emitters are spaced at 4”, 6”, 8” and 12” centers. This can be used in home gardens, but it is really meant for large commercial farms. Discovering T-tape led me to a local store that sold irrigation supplies and introduced me to a new type of drip irrigation.