How Can Pruning Affect Water Use?
A
recent survey of the landscape practices and preferences of 1800 residential
homeowners by researchers from Arizona State University has some very
interesting results.
• More homeowners preferred an oasis-type landscape design that combined both desert-adapted plants and a small turf area for recreation. However, it seems homeowners with programmable irrigation systems do not adjust their water applications to seasonal changes as recommended by horticulturists and water conservation offices.
• Also studied was the effect that frequent pruning has on a plant’s water use. Results show that frequent pruning increases the plant’s need for water as it produces new leaves to replace those lost. Plants given low irrigation volume and pruned only yearly had the highest water use efficiency.
• Plant appearance preferences were evaluated. Survey respondents preferred shrubs with a more natural shape to those formally hedged.
• When two yards containing typical desert-adapted plants were compared, the results were surprising. Although the front yards were similar in size and plant material, and contained no turf, the watering practices were dramatically different. One household applied 218,000 more gallons of water per year than the other - a difference of nearly 700%. But ‘no measurable or visible differences in plant appearance or fitness’ could be documented!
What does all this mean?
Many homeowners apply more water to their landscapes than the plants really need.
Most could safely adjust their irrigation practices and apply water less often without affecting plant appearance or health.
“Plants Don’t Save Water, People Do”
Source: Arizona State University Central Arizona - Phoenix Long-Term Ecological Research (CAP-LTER) project research vignette.