Risk Tree Evaluation

Living in a suburban or urban environment requires each property owner to make sure his or her property is in a safe condition for anyone who passes through. If a tree does fail and injures a person or piece of property the tree owner may face legal action. Whether it is negligent or not only the trier of fact determines. But one thing is certain, litigation in todays society is extremely prevelant.

THM has a standard tree risk management program for homeowners, municipal and large facilities. We have the equipment and expertise to effectively diagnose a specific trees mechanical strength. A trees mechanical strength directly indicates its ability to either fail partial (limb) or in total (from base of tres). Besides having the most up to date equipment we are expertly trained. In fact we provide professional development seminars on risk tree programs to garden clubs, allied professionals and educators as well.

The last thing any property owner wants is litigation. Call us today and we will set up an appointment to review your trees risk status. And we will review it regularly to make sure your trees stay safe and healthy.

divideEvaluation of the Resistograph
From City Trees, The Journal of The Society of Municipal Arborists
Vol 37, Number 5
September/October 2001

The resistograph is a tool that was developed in Germany and has been available for the past 5 years. It consists of a needle or drill-like device that measures wood resistance as it is driven into the wood. The needle bit has a diameter of 3-mm and can be 12″ long. As the needle penetrates the wood, the tool prints out a record of resistance. There is high resistance in sound wood and low resistance when decay is found.

A portable drill is a alternative tool that can be used to detect the pres-ence of decay. The drill should have a broad point drill bit. It’s diameter is 3.2 mm or 1/8 inch.

A study was conducted to deter-mine the accuracy of the resistograph and the drill. Both tools could detect advanced decay. The resistograph could detect moderate decay that the drill could not. There was a lot of variation depend-ing on operators, tree species, and time of the year.

This article is based on a talk by Dr. Larry Costello, who is an Environmental Horticulture Advisor with the University of California. Cooperative Extension.