A healthy tree requires the appropriate soil in order to thrive and grow. The soil must complement the tree’s drainage, nutrient and acidic requirements. A soil that retains too much or not enough moisture, along with an unsuitable pH level can have damaging, and sometimes fatal, affects upon the tree. Understanding the soil variations of your planting location will not only assist in selecting the ideal tree for the location, it will assist in maintaining a healthy environment and feeding schedule for the tree.
Sandy soils range from fine sandy loams to sandy. These sandy soils contain between 50 and 75 percent sand that is mixed with silt or clay and, at times, small amounts of muck. These soils have a lower, overall soil porosity, maintain somewhat dry water contents and do not hold nutrients. These soil characteristics are ideal for trees that prefer a moist to dry establishment with no wet feet. Ideal trees for sandy soils include most pine tree variations, red oak, white cedar and avocado.
Silt-based soils include silt, silty clay and silt loams. These silt-based soils have a higher porosity level and water content level than sandy soils but are very light and subject to rapid erosion. Silt soils consist of 50 percent or more silt content with clay levels of 15 percent or less. These soils are ideal for trees that prefer consistent moisture levels with a tolerance for wet feet, such as some evergreen variations, hickory trees and black birch trees.
Clay soils have high porosity and water content levels, much higher than sand and silt. These clay soils are heavy and dense and very hard when dry. Clay soils are categorized as those with 25 percent or more clay content with additional silt fillers. Trees that thrive in clay soils include most maple variations, river birch, hickory and most oak and elm variations.
Loamy soils are soils that include a combination of sand, silt and clay soils. These loamy variations may also include muck and organic compost. The combination of these ingredients promotes a balance between moisture and nutrient retention, good drainage and soil aeration. Loamy soils are ideal for most trees and plants, including the black walnut, European larch, Scotch pine and Norway spruce.