~From Roots to Shoots~
Soil Structure in Residential Landscapes
Many plant health issues are caused by compacted, poor-quality soil. When new plantings have difficulty establishing healthy roots, it creates stressful growing conditions. These types of situations often make plants more susceptible to insect and disease issues. Establishing the proper soil composition from the start will produce happier and healthier plants long term.
In the woods, leaves annually create an all-important organic layer that makes the soil fertile. This organic layer not only helps regulate soil moisture and temperature, but also improves soil structure by allowing room for air and water. In an urban landscape, we remove the leaves annually, therefore removing the natural organic material and depleting the soil of many benefits.
When we build a home and redesign the landscape, we destroy the natural soil structure and existing soil layers through excavation and grading. We dig through the layers, bringing less fertile soils to the top where roots are expected to grow after construction. Then we try to establish a new landscape in the backfilled soil. Contractors also compact the soil and grade it out to a desired layout. Compacted soils prevent air and water movement, which is important for root growth.
It is important to understand that 80% of soil compaction happens during the first pass of equipment. So even when soil is not moved, dug up, or graded, the movement of large equipment over an area can impact existing trees’ root systems negatively. So what can we do to improve the quality of soil with these issues? It’s really pretty simple: loosen the soil and add organic material. Mulch, wood chips, and leaf compost all make a great organic layer to top-dress the soil. We also employ soil-fracturing techniques, depending upon the degree of compacted soil and soil fertility. Methods include air-spading, tilling, vertical mulching, and soil replacement.
These soil improvement methods will show their benefits immediately. Loosened soil will allow for healthier root systems on your trees and shrubs.