Tree growth regulator (TGR) technology has been around for more than half a century. Reminiscent of many herbicide applications, TGR started out rocky and inconsistent, but has advanced into one of the most reliable and predictable means of tree maintenance.
It all began with the tragic pill/implant method. The active ingredient was pressed into a pill form and placed into a hole in the tree drilled by the applicator. If you were to cut into those treated trees today, chances are you might find the pill still intact. This method obviously resulted in inconsistent results, no results or had a negative impact on the tree, casting an unshakeable skepticism over the application of tree growth regulators.
Several years later, a similar method was introduced that also had the active ingredient being placed beneath the cambial layer, but this time it was in the form of a large syringe. A rigid needle was stuck into the side of the tree and the compound was administered via high-pressure injection. The results varied and many times the high pressure physically blew the surrounding bark off of the tree. There needed to be a less-intrusive method.
Today, tree growth regulator takes the approach of following the natural method of entry for the tree. Instead of force-feeding paclobutrazol to the tree, the TGR is injected around the base of the tree into the soil. From there, the tree naturally pulls the solution out of the ground through the root system and evenly distributes the treatment throughout the tree, much like it would distribute water or nutrients from the soil. This method creates a consistent control throughout the tree, giving you predictable results.
Over the past 10 years, Edko has successfully treated over a million trees utilizing the soil injection method for utilities all over the country, helping our customers achieve their clearance goals as well as their budget goals. The question is no longer “does it work?” but instead “when and where do you put it to work?” What history has taught us is that, like a good speech, it’s all in the delivery.