Since 2002 I have advocated the concept of feeding trees through the cambium via trunk applications over any other commercial model. This is not a technique that I developed, had any part of creating, nor had I ever heard of it before then. In fact, fertilization of trees (for me) prior to that was accomplished via granular delivery or deep root injection. Most often, the materials being applied were soil corrective rather than nutritive and were designed to help establish new plantings in less than ideal soil environments. Visually, the results were marginally better than trees that were left alone but at least we “felt good” about what we had done.

A tree product was introduced to me in 2002 that changed my whole perspective on arboriculture and what was truly possible. I was given a 32 ounce spray bottle with a trigger and told to spray the trunk of any ailing tree 6’ up or to the first fork. This product was an NPK balance with some sulfur but no other minors to speak of. An immediate and somewhat miraculous result took place. New plantings rooted very quickly and mature trees quickly added growth and color. The best part was that all this was done with very little input. The model of using this material in a full service application would be challenging as it needed to be applied at full strength concentrate and would destroy any metal it came in contact with.

I used this for two seasons and it gave rise to the development of a more user friendly and complete product that could be used in a diluted form, under pressure, and adjust soil deficiencies with a greater number of micros and organic material all at the same time. The results were astoundingly better. This was the birth of “3-0-1 Complete Landscape Nutrition,” the original product (comparable to the Greene County Fertilizer 4-0-2) and the one that was used for turf as well in the beginning. When placed into a tree and shrub fertility program, the 3-0-1 outpaced anything that it was ever up against. The first 10 Bio Green® Licensees kept incredible records of the results they were seeing via pictures and customer feedback and still this style of feeding trees was hard to grasp for anyone that had been doing deep root fertilization for any length of time.

It is important to understand how a tree moves nutrients and water and what exactly is happening in the vascular system that makes the whole thing tick. The vascular system, in plants, is an assemblage of conducting tissues and associated supportive fibers. Xylem tissue transports water and dissolved minerals to the leaves, and phloem tissue conducts food from the leaves to all parts of the plant. So while these two “highways” are conducting their cooperative jobs, there is another aspect that makes this “bark applied” nutrition work…. Water. In order for a tree to properly absorb nutrients through the bark, the Xylem needs to be properly hydrated. To accomplish this, our application rate calls for a good amount of water to be applied during the visit. A good soaking allows for some nutrients to be absorbed by running down into the soil around the trunk while the rest adhere to the truck and wait for absorption. This becomes an incredibly efficient and fast feeding system that any company can put into place for additional services and revenue.

When compared to deep root feeding, trunk applied nutrition will out pace production 50:1. The end results are faster and more efficient nutrient delivery, quick visual results for your clients, and noninvasive procedures that will not damage tree roots. The International Society of Arboriculture recognizes deep root feeding as a gardening myth stating, “You do not need to apply deep root fertilization to reach the roots, the most fibrous roots of a tree (and the ones who absorb the most nutrition) are located in the top 2-8” of soil.” In fact, it has now been concluded in a review of North American tree fertilization that surface application of nutrients is as effective as sub soil applications thus leading to the conclusion that deep root feeding is an outmoded and inefficient model for tree health.

I encourage everyone with a lawn care operation to consider adding tree services to their offerings. The overall value to your clients is significant and the increase to your bottom line is one that will make you smile when you are doing tree apps, rather than making your back hurt…