Articles > Irrigation for Sustainable Gardens


The way a sprinkler system is designed and installed affects the future maintenance of your garden as much as anything else.  This is not the place to cut costs and use inferior materials and inadequate installation as the veritable life of most of your garden depends on this watering system.  A poorly designed and or installed system will result in uneven coverage, water waste and dead plants far in excess of the money saved with a cheap system. A good sprinkler system will use the heaviest schedule pipe and fittings available commercially.  In addition all above ground sprinkler heads will have some kind of sturdy flex connection to the sprinkler lines to avoid expensive damage to below ground lines when heads are pushed or pulled around during maintenance operations.


Sprinkler positioning and spacing is both an art and science in itself. Heads should usually have "head to head coverage", meaning that each head can throw water over to the bottom of the heads next to it.  With trees and shrubs it is also critical to position sprinklers around their potential obstruction to avoid "rain shadows."  This is a real art requiring the irrigation installer to understand the lay out and eventual size of plants in the garden.  This is why the garden designer should also be involved in the sprinkler layout and/or the planting and irrigation should be done by the same contractor who should know the plant material very well.


Drip systems can save a great deal of water in landscape maintenance, and because of water restrictions are becoming increasingly the watering system of choice.  Drip systems are especially good for watering plants in pots, on steep slopes, in narrow areas, and drought tolerant plantings of widely spaced shrubs and trees.  susceptible   Proper filtration  and drainage of the system will avoid plugging problems with the emitters.

A garden irrigation system also must reflect the different water needs of different plant materials in the garden.  The irrigation system should be broken up into 'hydrozones' or watering zones so that high water use plants such as grass are on a separate zone than low water use plants.  A home garden will probably have two or three different regimes of high, medium and low water use. In addition, to maximize the efficiency of irrigation, manufacturers have introduced a variety of "smart" controllers that use either temperature and precipitation data from onsite or evapotranspiration data from a satellite feed connected to a state weather monitoring system. High tech has really come home to the landscape !

For more information please contact the author at:

Robert Cornell & Associates, Inc. 

Landscape Design & Installation

1211 Sinaloa Avenue   

Pasadena    CA   91104

phone 626.398.5581   fax 626.398.4421

Robert Cornell