Stately old oaks, maples and similar shade trees only look indestructible. In fact, if you have to dig a trench for piping or conduit through their root zones these trees can suffer severe damage. Whether doing the work yourself or overseeing a contractor, a little knowledge makes it possible to minimize construction trauma. Avoid damaging the roots by tunneling under them rather than through them.
Because most roots live in the top 18 inches of soil, a tunnel 2 feet deep often does little damage, says Dennis Schrock, extension assistant professor with the University of Missouri.
If possible, particularly if the tree is vulnerable, dig the tunnel 3 to 4 feet deep. At that depth it's unlikely you'll damage any tree roots.
In his "Preventing Construction Damage to Trees," Schrock recommends working at least 1 to 2 feet away from the tree trunk of small trees to avoid hitting any tap roots. And don't trench within 10 feet of a tree trunk that's about a foot in diameter; larger trees require even more clearance around them.
For more information, go to http://muextension.missouri.edu /xplor/agguides/hort/g06885.htm.
These books offer fresh ideas and information to help you improve and enjoy your yard and garden:
* "Better Lawns, Step by Step," by Joe Provey and Kris Robinson, is the most practical book we've found on growing a healthy, handsome lawn without wasting time and money. Excellent step-by-step photography illustrates how to fix and maintain an existing lawn, or plan and plant a new one, all without using highly toxic pesticides and herbicides.
* "Scarecrows," by Felder Rushing, is a compilation of history, lore and practical instructions for the entire family. Colorful photographs reveal a universe of scarecrows; detailed instructions show how to create 20 different figures out of recycled materials, ranging from tin cans to neckties and milk jugs.
* Ortho's "All About Sprinklers and Drip Systems" presents a number of irrigation options, from fully automated sprinkler systems to fine-tuned drip systems for containers. The book, by Larry Hodgson, tells how to plan and install an irrigation system, and when to get professional help. The book provides instructive photographs and illustrations as well as how-to tips.