Which Trees Grow Best in Which Kinds of Soil?
Parcels of land each have a particular soil profile based on their location and maintenance history, which affects the tree species that can grow there. Trees are adapted to the composition and behavior of the soil in their natural range, which may (or may not) limit their tolerance of other kinds of soils. In this article, we’ll go over the soil types found around Nashville, as well as which trees are best suited for those various kinds of ground.
What Does Soil Type Mean for Trees?
Some trees are highly picky about the soil conditions they can and can’t grow in, while others have more versatility and can thrive in a range of soil types (ginkgo and serviceberry, for example, are versatile trees that do well in a range of soil types). Soils can tend to be wet or dry, dense or loose, acid or alkaline, high or low in organic material. Many tree species are specialized and specific to particular types of soils but others are much more tolerant of more types. Some may be more tolerant of varying soil moisture levels, and some may be more tolerant of a wider range of pH.
The rate at which water drains is only one characteristic of soil that affects how a tree can grow. Soil is made up of mineral particles and organic material, both of which affect how much moisture and oxygen are held in and move through the soil mixture.
Mineral Particle Size
Soil can contain large pieces of stone (from sand to gravel) and small, fine pieces (like clay and silt). The particle size of the stone affects the texture of the soil and how easily water drains (generally, the larger the particles, the faster it drains). The length of time moisture is held in the soil has a significant impact on the health of trees; standing water may cause root rot or hypoxia, while too dry soil can lead to dehydration and root death, which can reduce the ability later to take water up when it becomes available again.
The main types of soil by texture are:
Clay: The smallest particles don’t filter water well, so clay-heavy soil holds the most moisture, creating a dense material.
Silt: These particles that are larger than clay but smaller than sand can get very wet, not drain well, and wash away easily.
Sand: Sandy soil drains quickly as water runs off the grains of stone. The amount of organic matter affects whether nutrients or moisture can be held for very long in sandy soil.
Loam: Loam is a mixture of sand, clay, and silt, holding some moisture while draining excess water. Loam also contains the most organic material compared to other types, resulting in the most nutrient-rich soil with this balance.
The mineral content of the soil affects how water behaves in the ground, but the other solid component of soil, organic matter, absorbs and holds moisture, balancing the effects of the hard stone particles.
Wetness and Dryness of the Soil
Certain environments are naturally wet, such as bottomlands, wetlands, and the land surrounding streams, rivers, and lakes. Trees that thrive in moist soils like clay and silt include:
River birch
Willow
American sycamore
Boxelder
Persimmon
Sweetbay magnolia
Other trees prefer well-drained soils:
Shortleaf pine
Southern red oak
Black locust
Osage orange
White oak
The amount of moisture that soil holds does more than hydrate a tree; the water contains leached nutrients from the organic components of the soil, which plants absorb through their roots for nourishment.
Soil Nutrient Content
Nutrients in the soil come from decomposed organic matter. Decomposers like worms, fungi, and bacteria, as well as larger wildlife like birds, mammals, insects, and other animals, make nutrients available from organic matter (such as grass, leaves, and berries), which tree roots absorb from the ground.
Nutrient-rich soils condition some trees to require good fertility, with a plentiful availability of vitamins and minerals, while other tree species are more efficient with nutrients and can tolerate harsher ground conditions.
The most nutrient-rich soil, with a balanced mineral composition of clay, silt, and sand, is called loam (which means “muddy earth” in Old English). Loam has a smooth to crumbly texture, holding moisture and oxygen in good proportion. It’s found in a variety of environments because it’s a balanced mix of its components.
Loam is considered the best soil for most trees because it holds moisture, drains well, and is rich in nutrients (although some trees do prefer drier or wetter conditions). Trees that prefer a rich, loamy soil include:
American basswood (Linden)
Apple
Pecan
Dogwood
Serviceberry
Arborvitae
Pawpaw
Certain tree species can tolerate poor-quality soils that are depleted of nutrients and/or contain little organic matter. While low-quality soil can be amended with compost and mulch to improve the ground, some tree species grow efficiently in these harsher conditions:
Eastern red cedar
Virginia Pine
Honey locust
Black locust
Chinkapin oak
Sweetgum
A tree’s access to nutrients may be determined by the amount of organic material present, the tree species’ efficiency, or the acidity level of the soil, which is affected by the type of organic matter present, the moisture level, and the types of minerals in the ground.
Soil PH Level
The pH of soil (how acidic or alkaline it is) affects nutrient availability because different nutrients are accessible at different pH levels. These levels can be tested with a soil test, which you can have done for you or by taking a sample and sending it to University of Tennessee Extension.
Some trees do best in ground that’s on the acidic side, such as:
Sweetgum
Dogwood
Birch
White pine
Red oak
Blackgum
Mineral content of soils affect alkalinity, and in Nashville, chalk and limestone (alkaline minerals) are common, creating high pH conditions in many areas. Species that prefer neutral to slightly alkaline soil include:
Eastern red cedar
American sycamore
Chinkapin oak
Honey locust
Hackberry
Catalpa
Osage Orange
Which Trees Are the Most Soil-Versatile?
Certain tree species are particularly hardy and resilient, and they can tolerate a range of Nashville soil types, from loam to clay and even sand. Some of these trees include:
Eastern red cedar
Black walnut
Hackberry
Honey locust
Shumard oak
American sycamore
Sweetgum
Red maple
White oak
Tulip poplar
Planting Trees for Endurance
Before choosing a tree for your yard, know your soil type! It will help you choose the right species for the location, where it will be able to thrive in its preferred conditions. Check out the Nashville Tree Conservation Corps’ tree sale to browse our variety of tree species for every soil type. If you can’t plant a tree, consider donating a tree for us to plant, or sign up to volunteer and lend a hand to care for and plant trees across Nashville.
You can also make a financial contribution to NTCC, which supports our all-volunteer organization in fulfilling our mission to support Nashville’s canopy over the long term. Sign up for our email newsletter to receive updates on our work in addition to useful information on how to best care for the trees in your yard and neighborhood.
Visit our Linktree page for more ways to connect with NTCC!