The root systems of some types or plants and trees can cause damage when planted too close to concrete or paver surfaces, home foundations or other walls, and septic systems. So you want to make sure you properly space trees and plants far enough away from these structures in order to avoid damage. When in doubt about how the root system of a specific type of plant or tree behaves in your area, and how far it should be spaced from certain types of structures, I always advise consulting with a local landscape designer, arborist, professional nurseryman or your local Extension Service Agent.
Below you'll find some basic guidelines and suggestion regarding spacing plants and trees from surface structures, walls and septic systems and lines.
Driveways, Walkways, Patios & Other Surfaces
How far to space a tree, shrub or plant from a concrete, asphalt, paver or other surface is fairly straightforward. To avoid damage to the surface structure from roots, you want to space the plant a distance from the edge of the surface at a distance of at least half the maximum width that the plant or tree will grow at maturity, more is better. Spacing should be "on center," which means from the center of the plant to the edge of the driveway or other surface area. That said, I always add a few feet for shrubs and 5 to 10 feet for trees to that distance because over time a plant or tree might grow a little wider than listed.
For example, if you are planting a shrub or tree that grows to approximately 10 feet wide at maturity, you'd space the center of the tree a minimum of 5 feet away from the edge of the driveway. If you want to be safe maybe add 2 to 3 feet to that distance and plant 7 to 8 feet away from the driveway.
Note: Some large growing trees have extensive root systems with large roots that naturally extend well beyond the drip line(branch perimeter). These roots can bulge above the surface of the ground and cause damage to concrete, pavers or asphalt surfaces. When in doubt about whether or not a specific type of tree can damage these surfaces, consult with a local arborist or professional landscaper as to proper spacing.
Home Foundations & Other Walls
How far to space a tree, shrub or plant from a home foundation or other wall will depend on the integrity of the wall and the type of tree, shrub or other plant. Some trees and shrubs, such as Japanese maples, crape myrtles and camellias, which are often used as espalier (trained to grow flat against a wall), can be planted very close to block or concrete walls with no worries about damage from roots. That said, if the block or concrete wall is old and has cracks that go all the way through the wall, roots can enter these cracks and possibly cause further damage to the wall.
As a general rule of thumb, if you are planting a shrub or tree that grows to approximately 10 feet wide at maturity, and you don't know for sure if the roots of the specific type of plant or tree are known to cause problems with walls, you want space the center of the plant a minimum of 5 feet away from the edge of the driveway, more is better. If you want to be more safe maybe add 2 to 3 feet to that distance and plant 7 to 8 feet away from the wall.
Note: Some larger growing shrubs and trees have extensive root systems with large roots that naturally extend well beyond the drip line(branch perimeter). These roots can bulge above the surface of the ground and cause damage to concrete or block walls. When in doubt about whether or not a specific type of tree can damage these walls, consult with a local arborist or professional landscaper as to proper spacing.
Septic Systems & Lines
How far to space a tree, shrub or plant from a septic system or septic lines depend on the type of tree, shrub or other plant.
Trees and plants that typically don't drink a lot of water should be spaced a distance equal to the listed width at maturity. If you are planting a shrub or tree that grows to approximately 20 feet wide at maturity, you want to space the trunk of the plant or tree a minimum of 20 feet away from the edge of the septic system or lines, more is better. If you want to be more safe maybe add 5 to 10 feet to that distance and plant 25 to 30 feet away from the septic system.
Trees and plants known to drink a lot of water, such as river birch and weeping willow trees, usually have much longer roots that will travel much further to a water source. These moisture-loving trees and plants should be spaced at a distance equal to at least 2 times their listed width at maturity. If you are planting a tree that typically grows 30 feet wide at maturity, we suggest space the trunk of the tree a minimum of 60 feet away from the edge of the septic system or lines, more is better.
Note: Septic systems can be very expensive to fix when damaged by the root systems of trees. Therefore, when in doubt about the root system of a specific type of tree or plant, we always advise to consult with a local arborist or professional landscaper as to proper spacing.
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