Above is a comparison of two root systems that were exhumed and cleaned with our supersonic air knife.
The root ball on the left is a tree that we were contracted to remove. According to the homeowner, it died approximately two years after being planting.. The tree was 2.5" caliper, planted from a "traditional" potted container. Although the tree was nearly 15' tall, it's root system never left the imprint of it's shipping container- it's just a mass of encircling roots beginning to girdle. There are no large structural roots forming to anchor the tree, and almost no fine absorbing root hairs to uptake moisture and nutrients. This poor tree was never going to make it, just due to its containerization. We were able to pull it straight from the ground with our machine.
On the right is the root system of a Legacy-Tree that took an unfortunate fall during unloading at our nursery, splitting the stem. This tree was 2" caliper, 11' tall, and had spent almost a year in its system. You can see the well-defined structural roots emanating from a healthy root flare like spokes of a wheel, engorged in absorbing root fibers. Had this tree not been damaged, it would have been off to a fantastic start. It is easy to see the difference created by the Legacy-Tree system.
Trees do not have a "tap root." In fact, almost all tree roots exist within the first ten inches of soil- where biological activity is richest and atmospheric exchange occurs. Planting a tree deeper than this level is bad for tree health for multiple reasons. First, the aggregate is unsuitable to support the needs of a tree, forcing it to expand its roots upward before they can even begin to perform their necessary functions. This places an immense amount of unnecessary stress on an establishing tree, often leading to transplant failure when compounded with other common planting malpractices, such as basal watering and root smothering (i.e. "watering bags"). But the most serious and lifelong issue created by the common industry planting method (deep-planting) is the submersion of the root-crown. The taper of the trunk into its leading roots is never meant to come into contact with soil- It lacks the same phyto-chemicals used by root tissue to fight off saprobic microbes and fungi. This places a tree in a lifelong battle for its base and root connections, robbing energy from other functions of tree health and significantly shortening a tree's lifespan. Trees that are deep-planted have less energy to put into forming healthy structure, defense against pests and diseases, and growth.
Trees in the forest will show you exactly how they want to be- just take a hike at beautiful Oxbow Park in Byron, MN or at Quarry Hill Nature Center right here in Rochester, and see for yourself. All of the magnificent stands of hardwoods have pronounced and well developed root crowns above grade. The deep-planting practice has only been in use since WWII, which is a reason why trees planted prior to this point in history have better structure and are often still around! A walk around the historic neighborhoods in downtown Rochester (Plummer Hill) will reveal impressive boulevard trees with their root-crowns at the proper depth.
Legacy-Trees creates an environment of containerization that focuses on root health, instead of working against it. The Legacy-Tree method places the root crown and system at their proper depths, with a planting process that maximizes root development, tree growth, and health.
Is all of this information new? The short answer is, "No."
While Ron Zillmer has been an early and continuing identifier of the issues created by containerization, knowledge of the science has become industry-wide in the arboricultural community. The link below is the International Society of Arboriculture's (the world's largest and most respected arboricultural accrediting body) planting instructions. It specifically addresses root-crown placement and planting depth:
So why, if this is proven science, are trees still being planted incorrectly?
One thing is for sure- incorrectly planted trees cost a lot of money. There are large costs associated with managing poor structure, improperly placed trees, administering treatments to trees with compromised immune systems, and ultimately removing and replacing improperly planted trees. A tree that is planted correctly, in the correct site for its species, and pruned early (by a professional!) will cost very little throughout the course of its long, healthy life. The arboricultural industry should be profitable because of tree health, not tree sickness. Arborwise and Legacy-Trees are putting tree-health first.
Ron dispels some myths about root systems