‘Native’ Plants Offer No Guarantee of Water Conservation

Gardeners looking for ways to beautify their landscape and conserve water should be aware that plants identified as “native” will not necessarily achieve their water-saving objective. 

Reported studies from the American Water Works Association Research Foundation and plant biologists at Arizona State University both found that so-called xeriscape or native landscapes were actually receiving more water than traditional style landscapes.  ASU scientist Dr. Chris Martin found that desert plants such as acacia, brittle bush, creosote bush and mesquite could use two to three times as much water as flooded alfalfa or turfgrass.

The problem is not necessarily with the plant, whether it’s a desert plant or a lawn, but with the watering practices of people.  Desert plants survive because they are capable of absorbing large amounts of water very quickly in order to survive in an area of infrequent rainfall.  However, when landscape water is made available, most plants can become “water-pumps,” absorbing water rapidly and growing at tremendous rates. 

Knowing the growth cycles and true water requirements of all landscape plants is a key to water conservation.  Even properly established turfgrass can survive on very limited water if it is allowed to go dormant during hotter, dryer times of the year, as long as the plant’s crown is kept hydrated with as little as one-quarter inch of water per week.