Are my trees stressed out?

Trees are an integral part of our natural environment having adapted and contributed to our southern ecosystem for hundreds of millennia. These giants of the botanic world come from humble beginnings, originating from tiny seeds. For a tree to survive in nature that seed needs to fall on soils that are conducive for its growth. Soil is the foundation of a tree’s health as well as the foundation upon which it sits and holds fast. Soil is a living ecosystem of its own filled with beneficial bacteria, fungi, organic matter, insects, worms, and larger animals like rabbits. These biological components depend on each other for food and in turn good health. When one or more of these components is missing or not functioning at its best the whole system is weakened, leading to the breakdown of the whole ecosystem. One way this ecosystem is harmed is through the use of herbicides, insecticides, fungicides, and high doses of inorganic fertilizers. Trees perform best in the woodlands not on the prairie. In the south we pride ourselves on having lush green lawns free of weeds. However, this is not a great environment for the same soil types that support healthy trees. We rake away the leaves as they fall onto the turf removing a critical part of nature’s recycling process. This removes organic matter that feeds the soil micro-organisms, it removes the minor elements needed as building blocks for the tree to use again the following year, and it removes the consistent available nitrogen source needed for tissue growth and photosynthesis. Is it possible to have healthy trees and healthy turf in the yard? Yes, it is! But this is a synthetic environment and requires an external input.
Can you think of a common synthetic ecosystem? How about a fish tank? Fish are meant to swim in the open waters of our oceans, lakes, and waterways but they can live long healthy and productive lives in a tank; provided we feed them, filter out their waste, provide light and darkness, heat, and air. The same goes for our trees planted in turf areas. We must provide them with healthy soils! Here are some rules to help you create a healthy soil for your trees. Number one, don’t plant or maintain turf right up to the tree’s trunk. Number two don’t use pre-emergent or post emergent herbicides near the tree’s base. Number three hire a professional to apply soil bio-stimulants to the critical rooting area.
What are soil bio-stimulants? They are what’s missing from the natural recycling process. Bio-stimulants are made up of organic food sources for the soil micro-organisms, high concentrations of beneficial living bacteria, micro-elements needed by the tree, surfactants to aide in moisture penetration, and low levels of organically derived nitrogen. Just like leaves fall every year these bio-stimulants need to be applied ever year to best mimic the natural processes. How are bio-stimulants applied? Arborists use specialized equipment that can pump the living liquid bio-stimulants into the critical rooting area of the tree. Special pumps are used, and the pressure closely monitored so that the living part of the mixture is not killed in the application process. The product is applied to the critical rooting area typically meaning that area under the tree’s canopy, just below the turf roots. Usually the product is placed about two inches deep (in the piedmont region of Georgia) but this depth can be more shallow or deeper depending on your particular region of the world. The product is applied using an injection tool that delivers about a pint of liquid product in a grid pattern three to four feet on centers into the accessible rooting area under the canopy. Some trees may need more intensive treatments than others but in general the annual application of bio-stimulants, in conjunction with good cultural practices is all that is required to maintain good soil, and in turn, good tree health.

Copywrite 2019 Robert Swanson ISA Certified Arborist.