The bulk of a tree’s roots grow in relatively shallow soil. And while this helps ensure they can access plenty of oxygen and grow through the relatively loose soil near the surface, it also exposes them to a number of potential problems. Foot and vehicular traffic, for example, can crush tree roots, sending trees into a downward spiral. Excessive temperatures can also cause problems for tree roots.
Fortunately, there is an easy way to protect and support your trees roots: Add a layer of mulch on top of the ground. Most mulches provide protection for these shallow roots and they even help to prevent weed growth under the canopy and keep the underlying soil healthier.
But while mulching properly can help improve the health of trees, improperly applied mulch can cause more problems than it will solve.
Identify the Areas Most in Need of Mulch
If you like, you could mulch your entire property – your trees would love it. However, this just isn’t realistic for most people, so you’ll have to determine the precise areas that you want to cover with mulch.
Minimally, this means covering the critical root zone – the area which contains the most vital roots — of your trees. You can identify this area pretty easily, just measure the trunk’s diameter about 1.5 meters above ground in centimeters. Multiply this figure by 12 and you’ll have the radius of the critical root zone.
For example, if your tree has a 20-centimeter diameter, the critical root zone forms a circle with a radius of 240 centimeters. This figure can help you calculate the amount of mulch you’ll need. Simply multiply the area of the critical root radius by 4 to 8 centimeters to obtain the volume needed.
Select the Right Type of Mulch for Your Needs
There are a number of different kinds of mulch available to home owners, including everything from straw to wood chips to shredded rubber. Each provides a different combination of benefits and drawbacks, which means they each excel in different situations.
Wood chips are the most popular mulches among most arborist, gardeners and landscaping professionals. Shredded wood and bark contribute organic material to the soil, help stabilize the soil temperatures, protect the tree’s roots and help to reduce the rate at which water evaporates from the soil.
The biggest drawbacks to wood mulches is that they break down over time, necessitating regular replacement. Different types of wood are used to make mulches, each of which offer their own pros and cons, so you’ll also need to decide whether you want mulch harvested from eucalyptus trees, pines or some other species.
Other types of mulch have their place, but most exhibit a few key problems. Gravel, for example, is great at protecting the roots of trees and many people like the way it looks, but it doesn’t contribute any organic matter to the soil and it doesn’t make a great moisture barrier.
Shredded rubber mulches help reduce the rate of evaporation better than gravel, but these types of mulches (which are typically a dark color) often become quite warm during long summer days, which can damage the tree’s roots. Nevertheless, gravel and rubber mulches essentially last forever, so they don’t require frequent replacement.
Spread the Mulch Properly
You’ll want to spread the mulch properly to ensure it achieves the desired effect. Start by spreading a 4- to 8-centimeter thick layer of mulch throughout the critical root zone. The thickness of the mulch layer is very important: Too thin, and it will fail to adequately protect the roots; too thick and it’ll starve the roots of oxygen.
But there’s one more thing you must do when spreading mulch under your tree. You must scrape away the mulch from the trunk of the tree. If you leave the mulch in contact with the tree’s trunk, fungi and insects may begin attacking the tree, eventually leading to its demise.
Of course, you don’t have to worry about mulching your trees if you don’t want to. Just contact your friends at Trav’s Tree Service and have tree-care professionals take care of all of your mulching needs. We’ll identify all of the areas in need of mulch, pick out the best mulching material for your property and apply it with skill and care.
You can just kick back and enjoy the results!