Late autumn through early winter is the best time to prepare trees for the upcoming winter and following spring. A professional arborist like those at Red’s Tree Service is your best bet to help tend the trees within your landscape. They can take proactive steps now that will help your shrubs and trees stay safe, healthy, and beautiful in the years to follow.
Winter weather characteristics like ice, storms, and rapid temperature fluctuations, both above and below zero, take their toll on trees across the Mid South. This is a stressful time even for some species used to colder regions. Residential trees that are exposed and isolated are particularly vulnerable, especially those that are young or newly planted and lack the mature defense mechanisms such as thick bark or a wide, spreading root system. Trees may be dormant during the winter, but unlike a hibernating animal that holes up in a snug spot, they are not protected from the elements. The raw intensity of the cold season directly affects trees.
Some of this stress is unavoidable when it comes to climate conditions, but there are still a few things you can do to minimize the stresses of winter and the damage they cause.
Cold Stress
There are a number of forms that cold stresses can take. The first is the rapid change between daytime heat and night time freezing on mature trees. Cracks can occur to the outer bark and inner wood called frost cracking or southwest injury (being this is the side that receives the most winter sunlight) from the stress that these temperature variations cause.
Unfortunately, there is little that can be done to prevent frost cracking in most situations. The tree is able to repair itself in most cases, although the cracked area remains vulnerable and major damage can happen if subsequent cracking occurs at the same place. In the case of palms and other tropicals, as well as young trees, the tree owner might consider a fall maintenance action like wrapping the bark. Products such as tree blankets are useful for this purpose. To reduce moisture the loss the application of a product like Wilt Pruf can prove to be beneficial.
The impact of sudden early frosts on late growth is another cold stress. Established growth on trees have time to prepare for cold whereas late season does not, leaving it more vulnerable. Cell walls on the new tips of branches can be ruptured due to ice crystals, and lead to die off the following season.
Wait until the tree has gone into dormancy for the fall before pruning. The risk of frost damages increase when pruning happens too soon because it encourages new growth. Shrub and tree roots continue to grow during the fall. Reserves of starch are stored for active energy in the spring when flowering, leafing, and shoot growth occur. New growth in the spring will be promoted by maintaining soil nutrient levels and increased root production due to fertilization. Proper fall fertilization benefits trees but try to avoid fertilizers with high amounts of quick release nitrogen.
Winter Drought
Drying out in the winter, particularly for evergreens, can be a real problem. This occurs when the ground is frozen and a tree loses more water than it can absorb. This is most prevalent when spring sun begins warming the rest of the tree but the ground remains frozen. The problem can be worsened by high winds.
In the late fall, lay down a layer of organic mulch around the base of the tree. This will act as a temperature buffer for the roots while slowing runoff and moisture loss. An anti-desiccant, which covers leaves with a waxy coating to reduce moisture loss, can be sprayed on broadleaf evergreens like mountain laurels, rhododendrons, and pieris to reduce moisture loss.
Sunscald
Bark cells can rupture and create cracks in the trunk when the winter sun thaws the tree by day and cold air freezes it at night.
A crepe paper tree wrap can be used to cover trunks and protects trees. Start at the bottom and wrap the trunk, then overlap layers by ⅓, and stop wrapping just above the lowest branches. In the springtime remove the wrap. Trees planted on the west or southside of a building are affected the most by unscald.
Branch Breakage
The winter months make branches more vulnerable to breakage. The wood hardens and becomes susceptible to wind damage because of its brittle state, this is particularly problematic in deciduous trees. Evergreens and deciduous trees can both be affected equally by snow and ice accumulation on their branches.
Good fall maintenance, particularly pruning, is key to minimizing branch breakage. The entire tree will be less susceptible to breakage if its weak and vulnerable branches are pruned, or if one limb from a pair sharing a deep-V crotch is removed.
Covering the entire tree in a sturdy tent-like housing is one solution that works well for very small trees and shrubs. Tying up and reinforcing branches with rope will work as a preventative means for larger evergreens.
Rodents
Rodents forage for the scarce amount of food available in the winter, which makes trees a target. Mice, rabbits, voles, and squirrels, as well as deer in more rural areas, will girdle trees and chew on bark. Outer and inner bark will be consumed, exposing inner wood. The tree won’t likely survive if chewing damage occurs halfway around the trunk.
Lay down mulch and leave a space between the mulch and the trunk of the tree to guard against mice, and check it frequently. You may have to set out bait to catch them if mice are proving to be a problem. Make sure to follow the directions carefully that come with the bait.
Wire mesh enclosures, like chicken wire, will deter rabbits and prevent deer from rubbing. You can block rodents by wrapping tree trunks in plastic tree guards, wrapping just above the snow line. There are also commercial paint-on repellants that are available.
At Red’s Tree Service, we know it can be stressful to plan your landscape for the winter ahead, and we want to help keep your trees healthy during the harsh winter months. Get in touch with us today or give us a call at 901.848.5323.