Before any work begins, a comprehensive evaluation consisting of a tree and soil analysis must be performed to accurately determine the suspected issues. Soil samples determine the physical and chemical properties of the soil, the treatment area, and level of amendments necessary to achieve the desired results. Treatment is frequently used on declining trees so an assessment of plant health, including pests and diseases that may cause the decline is critical during the initial evaluation.

 

Once the issues have been determined, the first step is to excavate the soil around the tree.  This will allow the arborist to see first hand if there are any structural root issues such as girdling roots, and/or any potential decay. This process can be as basic as using hand tools or as complex as using an air powered device. Air powered devices use compressed air so as not to damage the critical fine root fibers in the upper portion of the soil. The process also breaks up compacted soil as an added benefit.

 

One on the major issues with our urban forested trees and shrubs is soil compaction and lack of pore spaces. Sidewalks, driveways, new construction projects contribute to lack of poor space and the ability of the fine roots of trees and shrubs to expand past the drip edge of the canopy.  Breaking up the compacted soil with a high powered air tool introduces that much needed pore space for water and nutrients to inhabit. As we break up the compacted soil, we also add any nutrients that were determined to be lacking by the soil samples. Along with the nutrients, we also add compost and biochar. 

 

Biochar is a type of fine-grained charcoal used as a soil amendment and created by slowly burning wood and agricultural byproducts, such as plant matter, with low oxygen in a process called pyrolysis. Biochar holds water like a sponge, where plant roots can access it when they need it. This is especially helpful during periods of hot, dry soil conditions. It also helps conserve plant nutrients by storing them and making them readily available when plants need them. Road salt and deicing agents used for driveways and sidewalks can increase the salinity of your soil, making it harder for plants to take up water and nutrients. This dehydrates plants, causing them to wilt or brown. Biochar absorbs and releases salts in the soil to be flushed away in a way that reduces the injury to plants. It strongly resists compaction in soil, keeping channels open for water, air, and root movement even if there is repeated traffic on the surface. Furthermore, biochar sequesters carbon, storing it in the soil and keeping it from decomposing and adding carbon dioxide to the atmosphere.