Roots are the most important part of the tree
"A tree with strong roots laughs at storms" Malay Proverb.
Tree roots are easy to take for granted because we usually do not see them. Yet these roots are actually the most important part of a tree. A tree's root structure not only anchors the tree, keeping it from falling over in wind and storms, they also are essential in taking up the oxygen, water and nutrients that a tree needs to survive. Tree roots can also release chemical compounds into the soil around them that help protect the tree from diseases and certain pests.
Healthy roots mean healthy trees
Without a healthy root structure, you will not have a healthy tree. Certain trees like beech, cherry, plum, dogwood, magnolia and maples, are known for having shallow roots which grow laterally along or just below the soil surface, while other trees like white oak, sweet gum, hickory and certain types of pine are known for having deep, vertical roots. However, some natural factors, such as rocky or compacted soils, or a high water table can cause stunted, shallow or lateral root growth to occur even on trees known for usually having deep roots.
Landscape responsibly and know your tree's root habits
When planting near sidewalks, driveways, buildings foundations, sewer and septic systems or other structures, it is important to know the root growth habits of the trees you are using, as shallow, lateral roots can cause costly damage in time. It is also important to know about a tree's root habits if you plan to plant other plants around or near an existing tree. Oftentimes planting beds near or around trees can cause significant damage, or even death to the tree.
Nature takes care of tree roots, so should you
When you take a walk down a forest path, you will notice that mother nature does not place plants around a tree trunk in a perfect circle, like we humans tend to do. In nature, native plant species may dot the ground near certain tree bases, while the forest floor may seem quite bare around other trees. This is because some trees have denser canopies or higher water needs than other trees. These are also factors that should be considered when landscaping around or near trees in your yard to avoid harm to the tree and the other plants you intend to plant.
Common landscaping mistakes
Many popular shade or ornamental trees not only have shallow, lateral roots, but also have roots or trunks that are quite sensitive to damage. By placing the common, cookie-cutter planting rings of hostas around these trees, they may sustain significant root damage, which ultimately can lead to the slow death and decay of your important shade trees. Cutting or digging out an area around a tree for stone or brick retaining walls or plastic edging, oftentimes involves cutting into roots, basically severing the tree's lifeline which allows it to take up water and nutrients. Cutting into the roots can also leave the tree vulnerable to pests and disease. Remember essential tree roots can extend out much farther than the tree's dripline.
Damage to the bark or trunk could encourage disease
The same problems can occur when the bark or trunk of a tree is damaged by cutting, or digging; or piling soil or mulch too high around the base of a tree. Soil or mulch around the base of a tree can not only leave the tree vulnerable to pests and diseases but it can also cause the roots to grow abnormally, and lead to the girdling of trunk.
For best results and the continued health of your shade trees, do not build beds around trees that require you to cut or dig into the root zone for retaining walls and do not berm up soil or mulch around the base of the tree. Also keep in mind that trees need a lot of water to survive. Oftentimes they suck up so much of the water in an area that grass or other plants can't survive near them. Be certain to only plant near or around trees that you can easily reach with a hose or irrigation system. It also may help to plant only native, drought resistant, shade plants around or near trees.
Use small hand tools when you plant around your trees
Digging planting holes around tree roots can also cause significant damage to the tree. To prevent this, try planting small seedlings, plant plugs, bulbs, or plants with small root structures, to keep digging to a minimum. When you do need to dig, use a small hand trowel or garden knife, instead of a large spade which could cause more damage.
Taking care to avoid serious root damage from your landscape projects can keep your beautiful shade trees healthy for years to come. These tips can also help you to create beautiful, natural looking plantscapes and your trees, rather than the mediocre rings of hostas that adorn too many residential trees.