Irrigating a lush, beautiful garden on a hot, dry site can be a challenge, particularly with the water restrictions and time constraints that today’s designers and installing contractors face. Fortunately, if irrigated correctly, there are a number of drought tolerant plants that will thrive in these conditions and reward the designer with an easy to maintain and beautiful installation.
Drip irrigation is an effective and efficient form of irrigating these plants, in terms of water conservation, because water is not wasted by irrigating areas between plants or due to run-off, excessive evaporation, wind-effects, overspray and the like. Experience has shown that drip irrigation, when compared with overhead spray systems, is the most effective system of choice, in terms of water conservation and installed cost, where plant spacing is 2.5’ on centers or greater. While designing your “desert scape”, often referred to as “xeriscape”, keep in mind that, the further the plant spacing, the more cost-effective drip irrigation becomes, on a relative basis, when compared with overhead spray systems.
The use of rock as a ground cover is somewhat unique to desert scape’s, this sometimes poses a problem to thin walled polyethylene supply tubing, it is recommended that the thicker wall flexible PVC tubing be used. The flexible PVC has a much higher impingement resistance, in other words, if the supply tubing is buried directly underneath the rock, it is less likely that the flex PVC would be punctured due to someone walking on top of it.
The increased and random plant spacing of desert scapes lends itself to the use of on-line emitters that can be punched and installed wherever they are needed. It is important that you match the emitters flow rate to the plant that you are irrigating. More often in desert scapes, there are large differences in the amount of water that drought tolerant plants need.