Donna C. Fare and Wayne K. Clatterbuck University of Tennessee
Trees enhance the beauty and value of homes, streets and communities. However, trees planted in the wrong place can cause property damage and become a detriment rather than an asset. Carefully planning the location and species of a tree will ensure that the tree will be an asset and not grow into a hazard or a nuisance. Before choosing a tree, consider these factors:
- Purpose for planting the tree,
- Soil conditions,
- Tree location (the right place),
- Species growth and form (the right tree), and
- Undesirable species traits.
Purpose for Planting a Tree
Trees provide many benefits for the home landscape. Shade, color, vertical dimension, soundproofing, cooling, beauty, screening, windbreaks, boundary lines and wildlife habitat are just a few. Tree use is varied: framing the view of a house or landscape, screening out eyesores, dividing the landscape area, creating privacy and conserving energy. Landscape trees can be shade trees, flowering trees, framing trees, border trees, street trees, patio trees, fruit or nut trees and wildlife trees. Trees may also enhance property values. Once the purpose of the planted tree is determined, then other factors should be used to select the right tree.
Most trees grow best in a moist, deep, fertile, well-drained soil. Unfortunately, these soils do not occur frequently on developed property in urban areas. Soil conditions are probably the most overlooked factor when selecting a tree. Both the physical and chemical properties of soils in developed areas have usually been altered which affects fertility, aeration and drainage. Choosing trees that are best suited for the soil conditions on your property will govern how well they grow and prosper.
Soil fertility can easily be judged with a soil test. Soil tests will give indications of available nutrients, soil pH, and organic matter content. Contact your county AgriLife Extension office for soil testing information.
The physical aspects of the soil include its volume and texture (amount of sand, silt and clay). These soil properties influence aeration, internal drainage and water-holding capacity. The optimum soil for tree growth has a loamy texture (mixture of sand, silt and clay). Some tree species can better tolerate clay soils; others are more suited to sandy soils. Compaction of the soil decreases pore space and stresses the tree by reducing the amount of oxygen to the roots.
Tree Location – The Right Place
Growing space both above and below ground should be considered when selecting a tree to plant. Too often allowances are not made for the increased size of the tree when it matures. Some of the problems that can be avoided by selecting the proper tree for the available planting space are:
- Damage to houses through cracked foundations, leaves in gutters or abrasion of tree limbs hitting the house;
- Cracked pavement of sidewalks, driveways, porches and patios;
- Sewer lines or septic tanks clogged by roots;
- Dangerous screening by obscuring traffic signs, pedestrians or vehicles;
- Storm damage and electrical problems from trees or limbs affecting utility lines; and
- Blocking scenic views or windows.
One objective for planting trees in a residential setting is to provide shade to cool homes during the summer months. For morning shade, plant trees on the southeast exposure of the house. For afternoon shade, trees should be planted on the southwest exposure. Deciduous trees (those that lose leaves during the winter) allow the sun to warm the house during winter and shade it during the summer months. Evergreen trees planted on a northern exposure will screen or block cold winter winds.
Remember that trees will become larger with age. Your evaluation of the site before planting will allow you to choose the correct size of tree for the site, avoid crowding before it occurs and save time and money at some future date.
Species Growth and Form – The Right Tree
Once the soil and site conditions for tree planting are determined and evaluated, then homeowners can factor in their personal preferences when choosing a species of tree. Characteristics such as tree shape, size, flowering, colors and texture should be considered. Trees must be selected carefully in order to accomplish their intended purpose satisfactorily, and to continue to do so with future growth and development.
Tree Shape and Form
Different species of trees have different crown forms, such as round, oval, weeping, and pyramid, columnar or spreading. Selection of a proper form will satisfy your landscape objectives, enhance your property and decrease future maintenance costs. Trees with low-spreading branches are suitable for screens, but not for placement along driveways where visibility is essential. Columnar or upright trees are appropriate for medians and property boundaries, but not for providing shade for a house.
Tree Size, Growth and Longevity
Always plan for the growth and future size of a tree. The small trees planted today may be the large trees of tomorrow. Evaluate the mature height and spread of the tree, as well as its lifespan. Some trees grow and provide shade quickly within 30 years, then decline and eventually die. However, the growth rate and size of the tree may be acceptable as a yard tree during its first 50 years for shade and enjoyment. Thus, consideration should be given to whether the tree is planted for posterity or to fulfill an immediate need that may have future consequences.
Some trees are more adapted to certain intensities and amounts of light than others. Shade tolerance is a term used to rate the capacity of a tree to develop and grow in the shade of other trees.
Undesirable Species Traits
Most trees will have some undesirable traits that may be considered obnoxious by some and tolerated by others. Most of the unfavorable traits are associated with insects and disease, production of fruits and seeds and tree maintenance.
Insects and Disease
Trees are susceptible to many insects and diseases. Most of these problems are species-specific and should be considered when selecting a tree to plant. Consult with your local garden center, nursery, tree care professional, county AgriLife Extension office or forester to discuss if a tree being selected is prone or sensitive to local diseases or insects.
Fruits and Seeds
Some fruits and seeds are nuisances to property owners, but may be valued by others. If the homeowner is interested in providing food for wildlife, fruits and seeds will attract many birds and animals. However, some seed can annoy landowners.
Tree maintenance is an unavoidable task that homeowners should include in their evaluation of a tree. Most fast-growing trees will require more frequent maintenance than species with moderate to slow growth. The weak wood of many fast-growing trees requires heavy cleanup of limbs and debris after storms and may disrupt utility service and highway traffic.
Once the tree is selected, purchased and planted, considerable costs have already been incurred. If the tree is not suited for the growing space or location, it may not survive, resulting in a loss of time and money. If the tree survives, but was poorly selected, the homeowner or community will have considerable expenses for its care. The right tree in the right place will provide benefits for many years with minimum costs.