I was on the Arborists Online Facebook page a while ago and came across postings from a couple of young arborists. They had just received their copies of Dr. Alex Shigo’s books, A New Tree Biology and Modern Arboriculture. I could sense the excitement in their posts, and it brought back a flood of memories for me.

In the latter 1970s and into the early 1980s, I began reading the Journal of Arboriculture our parks superintendent, who oversaw the urban forest at the time, had been receiving. I was a city gardener at the time. In those days, Dr. Shigo was the chief research scientist for the USDA Forest Service. His early work on compartmentalization of decay in trees (CODIT) and his proposed method of natural target pruning intrigued me. At that time, it contrasted with Dan Neely’s (Illinois Natural History Survey) ideas on flush cuts. It wasn’t hard to see that arboriculture was changing and its practices evolving.

I became hooked, so much so that, when the opportunity arose in March of 1986, I signed on to the city’s tree crew. By June of 1986, I had completed both the first and second series of the then National Arborist Association’s (now TCIA) Professional Home Study Program. Shortly thereafter, I was promoted and given the title of urban forester. My career and passion for all things trees took off. I became an ISA Certified Arborist in 1996.

Things kept falling into place for me. In September of 1986, shortly after Dr. Shigo retired from the forest service, I attended his first New Tree Biology workshop in Chicago, Illinois. Imagine my surprise and great pleasure when I met him in the hotel cafeteria – and he invited me to his table! What a wonderful man. He was so personable, asking questions about me and my family, telling me a little about his and sharing a story about the work he did in Australia diagnosing a degenerative root disease among the eucalyptus trees. This disease led to a malnutrition problem with the koalas, whose diet is almost exclusively eucalyptus leaves. The koalas had to consume more and more foliage to acquire the nutrients they needed, which in turn gave them diarrhea, referred to as wet butt disease.

I followed Shigo’s work and purchased his many books and publications over the next 20 years. I was fortunate enough to meet him again at a lecture sponsored by Rainbow Treecare Scientific Advancements, a 23-year TCIA corporate member company based in Minnetonka, Minnesota, and at an Iowa State University Shade Tree Short Course. He had a way of making more complicated concepts easier to understand.

Some of his more notable books include: A New Tree Biology, A New Tree Biology and Dictionary, Modern Arboriculture, Tree Pruning, Tree Anatomy, Tree Pruning Basics, Tree Biology and Tree Care, Tree Basics, Tree Pithy Points and The Nature of Tree Care, as well as the American Forests’ publication, A Journey to the Center of a Tree.

My lifetime career path and passion for trees I attribute to Dr. Shigo. I hope his name still inspires young arborists today to seek out this great body of knowledge. His advancement of the science of tree care appropriately earned him being dubbed the “father of modern arboriculture.”

Dr. Alex Shigo died 15 years ago this month, in October 2006.

I can’t help but wonder where we would be today if he were around continuing his research, lecturing and publishing his works. His message to arborists everywhere still holds true today: “Touch Trees!”

Steven Pregler is an ISA Certified Arborist and retired city forester for the City of Dubuque, Iowa.

For more on Dr. Shigo, see the tribute to him in the November 2006 issue of TCI Magazine.