How Drip Systems Work

The Benefits of Drip Irrigation

• Using drip irrigation reduces evaporation as it applies water in individual spots around the plant directly at the root zone. No water is lost in areas where plants are not growing. Additionally, there is no run-off associated with drip emitters, so you are not wasting water by forgetting to turn off a hose. Another bonus with drip emitters is reduced weed growth in between plants. Moreover, plant growth is increased since tests prove that long, slow application of water encourages more extensive root systems which, in turn, are more drought-tolerant.

Drip Irrigation Equipment

• A drip irrigation system operates with low water pressure, working with less than 10 pounds of pressure. Since most homes have water pressure at around 60 pounds, drip systems require a pressure-reducing valve. This is located at the water source and is used for the entire system. There is also a controller that tells the system's valves when to turn on and off. A typical home drip irrigation system should have at least two separate valves attached to the irrigation lines that deliver water to the drip emitters. Trees should be on a different valve and schedule than shrubs and ground cover because they require a longer application rate with their more extensive root system.

Location of Emitters

• Drip system emitters should be placed at the base of new plants. Unfortunately, many times homeowners do not realize that emitter placement needs to be adjusted as the plant matures. Not only do the emitters need to be moved away from the base of the plant, but more emitters need to be added, especially around trees. As plants mature, their water requirements go up, at least to the point where they start to level off at full maturity.

Size of Emitters

• Drip emitters come in at least two sizes, with 2 gallon per hour (GPH) and 4 GPH as the standard. Note that these are gallons per hour, not gallons per minute, which is how sprinkler systems work. This slow delivery is what makes them so efficient. The number of emitters needed (and size) per plant are determined by whether the plant is new and the diameter of the canopy. A basic rule of thumb is the emitters should be placed where they will deliver water sufficient to saturate the root ball and just slightly beyond.