By Mike Graham, CLP, CLT, CA 

As a commercial property manager, one of the largest annual expenses to budget for is landscape management. Recent studies by the University of Clemson and the University of North Carolina Chapel Hill estimate the value of a professionally designed, installed and maintained landscape can constitute as much as 11% of the overall commercial property value of a suburban office building.

In terms of visual impact and initial cost, trees are the focal point in which the majority of commercial landscapes are designed around. Because of the important role trees play in the property's appearance, most property managers budget for tree fertilization, pruning and replacement. One line item that is usually overlooked but can play a crucial role in the overall health of your tree, is summer watering. The heat wave we are currently experiencing is taking a heavy toll on both recently planted trees, those that are one to four years old, and established trees five years and older. The combination of record heat with little measurable rain is both killing trees outright and pre-disposing trees to future disease and insect infestation.

An immediate problem that is showing up throughout the Chicagoland Area is "leaf scorch".
Leaf scorch occurs in hot, dry weather, particularly if it is windy. Under these conditions, large quantities of water evaporate from the leaf surface, and the roots are unable to furnish sufficient water to compensate for this loss. Since all of the leaf area cannot be supported, some leaf tissue dies.

Newly planted trees or trees growing under adverse environmental conditions are more likely to be affected by scorch than vigorous, well watered trees. Some of the adverse conditions that cause scorching are a dry, windy exposure, excessive fill over the roots, injury due to construction, and previous disease or insect damage. Leaf scorch sometimes occurs only on the south or west side of the tree, where wind and light intensity are strongest.

Trees affected by scorch may lose many leaves by late summer or drop leaves earlier in the fall.The added stress caused by leaf scorch can set up the tree to future disease and outer branch dieback. As a commercial property manager, one of the best ways to insure the health of your trees is to budget for and provide your trees with weekly watering during the crucial months of July and August. As a rule trees require 1" of rain per week during the summer months. Prior to onset of the hot months ask your landscape contractor to walk the property with you to determine which trees would benefit most from a mid to late summer watering program. In general trees that have been planted in the last four years, planted on berms, located in or around parking lots, and trees installed in exposed or windy locations are the best candidates for effective summer watering. The old adage "an ounce of prevention is worth a pound of cure" rings true with budgeting for tree watering. By watering your trees during the hot months you can improve the overall health and appearance of the trees. A healthy well watered tree can ward off disease and insect infestation avoiding expensive pesticide applications.

With the current nationwide shortage of plant material and corresponding price increases, avoiding unnecessary tree replacements can save thousands of dollars on your annualbudget.With the introduction of "Tree Gator" watering bags in 1996, the guess work has been taken out of watering newer trees. Usually by filling the bag once a week, the tree receives the right amount of measured water to help it through the high heat stress periods of mid and late summer.

Costs for tree watering vary from contractor to contractor. Usually an hourly rate will be given based on either using on site water or tank trucks. In the long run both your trees and your bottom line will thank you for initiating a summer watering program.

If you have any further questions about budgeting for tree watering, you may contact Mike Graham at Landscape Concepts Management, Inc. at (847) 223-0900 (extension 114).