From stem girdling and root collar excavation to soil aerification and tree fertilization, Vineland’s ISA Certified Arborists have you covered.
Research at the University of Minnesota has shown that trees growing in landscape settings are prone to a phenomenon called stem girdling roots (SGR). An SGR is a root or roots that grow around the base of the tree instead of away from the tree.
As the roots grow larger, they compress the stem like a tourniquet, cutting off the upward movement of water and nutrients to the top of the tree while preventing the transfer of photo-synthates (carbohydrates) from the top to the root system.
SGR leads to the decline of tree health, often killing significant portions of the tree. It may eventually kill the entire tree depending on the extent of the girdling of the stem. Trees with SGRs are also more prone to being blown over, even in a light wind, as the integrity of the stem and root system is compromised.
A root collar excavation is an exploratory, diagnostic procedure using compressed air to remove the soil at the base of the tree. This allows an arborist to identify and remove roots with the potential to cause stem girdling before any significant damage occurs.
It’s a process best done on young trees as a preventive measure, rather than on older trees as a therapeutic process. Therapeutic removal of SGRs is possible. However, the success depends on the extent of the compression of the stem and how much the overall health of the tree has been compromised.
Trees require water as well as oxygen in the soil to maintain healthy growth. Construction activity (driving or parking vehicles, staging materials, grading the soil under or around trees, etc.) compresses the soil, limiting the amount of pore space between the soil particles. The very fine roots of trees that are responsible for absorbing water, nutrients, and oxygen grow in these tiny spaces.
Construction activities not only damage the soil structure but can crush and kill fine roots. The purpose of treatment is to loosen and aerify the soil, recreating the soil conditions that are conducive to the regrowth of the damaged roots and speed the tree’s recovery.
Because trees store energy, the effects of damage to the root zone often do not become apparent for several years. By the time damage is apparent in the canopy of the tree, it’s too late to reverse the decline and the tree eventually dies.
Soil aerification and decompaction involves taking up the sod over the root area in long narrow trenches (or sometimes pie-shaped wedges) radiating out from the stem of the tree to the edge of the canopy. Compressed air is used to loosen the soil around the existing root system. Sometimes compost and organic-based fertilizer is added to enhance the existing soil structure and encourage redevelopment of the root system. The sod that was removed is then re-laid over the trenches.
Trees evolved in forests where leaves and other natural debris remained where they fell. The decomposition of these elements acted as a natural fertilizer by releasing nutrients back into the soil. Keeping a well-maintained lawn inadvertently deprives trees of this recycling process by removing the source of natural fertilization.
The lack of natural fertilization is difficult for urban trees. So is heavily compacted soil. Forest-grown trees benefit from naturally de-compacted soil, resulting in a larger number of roots that absorb naturally produced, fertilizing nutrients.
Soil amendment helps alleviate these problems for urban trees. Soil is de-compacted in radial trenches surrounding the tree. Organic fertilizer and other beneficial matter are added to the soil, creating a healthy environment for root growth. Vineland Tree Care practices this type of organic soil amendment and tree fertilization for both commercial and residential properties in the Twin Cities area, helping trees flourish in urban, non-forest settings.
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