Trees are like icebergs; much of what happens, happens below the surface. When you look at the trees on your property you see the leaves, buds, branches, fruit and flowers but you do not see the roots. You can’t see what is going on below the ground, but the root ball of a large healthy tree can be up to ten times the size of the parts of the tree that are visible above the ground. Just because the roots are under the ground does not mean that they can’t be damaged in the winter. Root damage from the cold can vary from mild to severe, and in extreme cases, the only solution will be complete tree removal.
The roots of a healthy tree are notoriously difficult to study, but ecologists have been measuring and documenting root activity of container grown trees for years and are now using modern imaging technology to observe roots growing and they have a fair idea of what tree roots do throughout the year. According to research, root activity is periodic. Maximum growth typically takes place in summer, but additional growth can occur before the winter sets in. However not all roots grow at the same time or pace and even in one tree, some roots will grow more than others.
What Happens to Tree Roots in the Winter?
In the winter it seems the roots of trees in cold climates become predominantly dormant. Like the branches above the ground, the roots spend the majority of the winter months resting and full root growth only starts again in spring when the ground is no longer covered in snow, ice and frost.
But, unlike the parts of the tree that are visible, the roots appear to be ready and able to grow at any time, regardless of what is going on above the ground. This means that while the roots don’t grow much in the winter if the soil temperature increases the roots will break dormancy and grow, even if the temperature above the ground remains bitterly cold. The ability to grow if conditions are favorable is important for the health of trees as it allows the root system to expand and find water and nutrients in anticipation of bud break in the spring.
Tree roots may be ready and able to grow at any time but unfortunately, they are not as hardy when it comes to surviving the cold as the trunk and branches. When the soil temperature drops below 20°F the roots can freeze and die. If the soil is well insulated by a layer of snow after a heavy early snowfall, winter root activity can continue and help replace roots damaged during the year as well as prepare the tree for spring. However, a heavy snowfall late in winter can keep the soil frozen for a long time and the roots will remain inactive well into early spring and that is not good news for the tree.
The freezing and cracking of winter soil is particularly harmful to shallow roots, damaging the fine feeder roots that are typically found in the upper layers of the soil and negatively affecting the tree both above and below the surface. Winter root damage will curtail the growth of trees in spring and in extreme instances, it will severely damage or kill your trees. In these cases, you will require the services of a tree removal company.
How to Protect Your Tree Roots During the Winter
The winter months are hard on trees and it is important to do everything you can to prevent the roots from being damaged by the cold. Deep root fertilization in early spring can help feed and strengthen the roots, making them less vulnerable to the freezing temperatures in winter. You can also protect your tree's roots with a thick blanket of mulch. The mulch needs to cover the area at least two feet around the base of the tree but make sure that it does not touch the trunk as this can cause the trunk to rot. It is also important to keep the ground around your trees moist and mulch will prevent excessive moisture loss.
At Martin’s Tree Service we are dedicated to protecting your trees. Call us for all your tree care needs and to discuss emerald ash borer treatment options.