8 Tree Myths DispelledBy Sheereen Othman (see entire article on www.TreesAreGood.org)
There are many myths in the world of trees, and it’s not until new research is uncovered that we realize our perspectives of trees are all wrong. Here are 8 common tree myths that give a bad rep to trees and challenge what you thought you knew.
Municipalities have a legal responsibility to keep streets safe, including preventing tree limbs and foliage from being hazardous to the road. This includes preventing obstruction of street lights and views of oncoming traffic, and preventing limbs from dropping. It also includes keeping a clearance of eight feet over sidewalks and 14 feet over streets. Maintaining the clearance can be challenging with newly planted trees that can not be pruned to height or mature trees that were improperly pruned in the past. When properly cared for, trees aren’t a nuisance and don’t hit or smash things such as cars, houses or poles.
Roots surface and damage lawnmowers
Many people may complain of tree roots coming to the surface and preventing grass from growing and damaging lawn mowers. In reality, under good conditions tree roots grow through the soil, not on top of it. Sometimes in nature roots are forced near the surface by shallow rocks or a high water table, such as in swamps. However, in community settings roots grow well beneath the surface. Root surfacing is often result of a combination of construction and compacted soil, leading to erosion which can surface tree roots.
Trenching and tunneling near trees is fine
In continuation to myth number two tunneling or trenching near a tree is not good idea. Roots are what keep the tree alive, and cutting near it only endangers the tree’s life. Even the tiniest slit made to bury a sprinkler system or to install a telephone line severs roots. When a root is cut, it is cut. To prevent damaging trees with trenches, detour around the dripline of trees and tunnel when roots cannot be avoided.
Tree roots cause sidewalk damage roots-under-sidewalk
Tree roots may start to extend under pavement if the slab isn’t thick enough and if it is built too close to trees.
Trees are often mistaken as the culprit for cracking sidewalks, but there is a much deeper problem at hand, and it isn’t trees. Steve Sandfort, an urban forestry consultant explains that often communities use the same construction design in building sidewalks when in fact the same design shouldn’t be used because there are differences in soils (such as soils of a high swell and shrink nature) throughout the city that will impact construction. So how can communities know of these soil variations? The USDA Natural Resources Conservation Service offers soil survey maps that illustrate these variances. As a result of poor design and soil conditions, roots often follow the gaps created as poor pavement heaves and settles.
Tree stakes are essential
There is partial truth to this myth, tree stakes may be necessary when strong winds are present or when seedlings are first planted. But even then, it is important to remove them after the first year. Often times tree stakes are installed and then forgotten about which can lead to root girdling as the tree grows. Improperly installed stakes can also reduce the natural sway of the trunk necessary for good taper and strong wood.
If it’s by my house, it’s my tree
When you moved into a new house did you wonder whose responsibility it was to care for the front yard tree—yours or the city’s? While it will vary in each community based on its ordinance, in most cases trees on the street easement or right-of-way belong to the city. This is true regardless of who planted the tree. Knowing who has the responsibility for street trees in your community is important in determining who should prune and care for trees, who is likely to be liable if an accident occurs and who pays for tree work or removal.
Water is a tree’s wonder drug
Ooze tubes, or watering bags, are a good way to control how often and how much water your tree receives.
It’s true, water is important for preventing stress that can lead a tree to disease, insect infestations and early decline. It is also essential at the time of planting to remove air pockets and to give the tree a good start. But as the proverb states, too much of a good thing can be bad. Many urban foresters will testify that more trees drown than die of drought, and this is result of overwatering. Watering should only be done during long dry spells, especially if windy or hot and dry climates are dominant. A large, newly planted tree needs only 10 gallons of water a week in dry weather—the equivalent of two flushes of a toilet.
Tree roots break sewer lines
Most roots are found within the top 24 inches of soil, away from sewer lines. In unique cases roots may grow deep enough to be near a buried sewer line. Even in instances where roots grow deep, they are not damaging to sewer lines until a sewer pipe breaks or its joints leak. Only then do the roots start to grow toward the pipe in search of moisture and nutrients, eventually blocking the flow of sewage. But trees are not the cause of broken sewer lines. On the contrary, when you think of water lines it may be hard to recall an example of a tree breaking through, even though these pipes are also filled with water. That’s because water lines are made of cast iron and designed not to break or leak. Whereas sewer lines are generally made of clay tiles glued together. Problems can be prevented by repairing or replacing defective sewers, proper construction of new sewer lines and finding ways to improve sewer design and construction.
Recognizing myths about trees and tree care is a result of continuing education and learning. When properly cared for, trees do not harm structural surroundings. It is often poor construction and design that leads to trees growing in places that are not tree friendly.