Caring for Your Fruit Trees Through the Winter

Fruit trees are a joy to care for, and the return can be just as wonderful. If you are serious about growing fruit trees, and want the best quality fruit from your trees, then caring for them shouldn't stop at the end of growing season. There are several things you'll need to be prepared for and multiple approaches to protecting your trees through the winter, giving them the best start in the next growing season.

One of the biggest concerns to growers throughout the winter is protection of their trees from rabbits, mice, deer, and a multitude of other hungry little creatures. Fruit trees, especially the younger ones (from one to three years old) have a really succulent bark that rodents like to chew on. Some will even burrow down and chew portions of the roots. This kind of damage may kill or severely weaken your trees; making them more susceptible to breakage or secondary organisms, such as fungi and insects.

Some form of pest prevention during the winter months is a must, it doesn't take much for rodents to irreversibly damage a healthy fruit tree. The most effective thing you can do is to remove all forms of cover for the animals. Try to keep the grass low and snow away from the base of your trees; and if you mulch, pull it back to a least five inches. You should also always make sure that an annual cleanup is done to remove left behind fruit and twigs from the ground that might further entice animals to your trees.

Most owners will place a plastic or chain guard around the bottom, covering to a height of at least 18 inches and completely encircling the trunk. I have also seen trees with rocks piled at the their bases. Nevertheless, It is important that you regularly inspect the ground around the trees for tunnels in the grass or holes that would indicate activity. If you find any, try using some snap traps. I have also herd of people using a sonar device to drive away persistent rodents, though I am not sure if this would be effective in bigger orchards.

Deer can also be a problem when rutting season arrives. Buck will rub their horns against nearby trees, leaving behind a strong pheromone to ward off other invading buck's. If you think you might have a problem with this you can cover the entire tree with a burlap sack if possible, then spray the burlap with fish meal. Fish meal has a really overbearing scent to dear.

In really cold climates, or on warm winter days, you also need to protect trees from sunscald. Sunscald can occur in late winter while the roots are still frozen. What happens is that the sun warms the bark during the day causing cells to come out of dormancy, then as night comes the freezing temperature kills those cells, which can result in water flow to the top of the tree being cut off. Consequently, much of the tree top dies back, and again, the tree is weakened and becomes susceptible to other organisms.

The best methods of preventing sunscald involve reflecting the sunlight or insulating the trunk. One of the most popular among big orchards is the use of white latex paint, spread over the entire trunk and sometimes up past the first few branches to reflect light away. Home owners with just a couple trees might be more attune to investing in some crepe paper to insulate the trunk. This tree wrap, available at local garden centers and nurseries, will help keep trunk temperatures cool. Otherwise, a tall plastic guard or aluminum foil works good to keep trees shaded and less susceptible to sunscald.

In late winter and early fall another potentially harmful aspect presents itself. As your trees are beginning to bloom, it is important to watch for signs of an impending frost. The news or weather channel will usually report when you should take the necessary steps to protect your plants, but a good indication of the onset of frost is a clear, starry night sky; given that the clouds are what holds heat close to the ground. A frost will severely damage, if not kill, any buds and fruits on your trees by absorbing the moisture right out of them. As a pre-emptive measure make sure that your trees are watered well into mid-October so that the they go into winter with a good moisture supply. This will benefit your trees in more than one way.

The most widespread method of frost protection is to cover the entire canopy of the tree with a burlap sack, or, if the tree is to big, you can try a bed sheet or similar light weight cover. Another method I see that is popular in big orchards is the use of a large fan to circulate the air and keep frost from settling, or a heating system to prevent temperatures from dropping to low. Others will spray a mist over their trees that will keep the frost from killing any buds. If you do end up missing a frost you can do a little bit of damage control by spraying water to try and replenish some lost moisture, but the effectiveness of this really depends on how much the frost has set in.

In addition, an overlong or short winter season causing a too short or to long dormancy becomes the foundation for several problems; such as delayed and extended bloom, delayed foliation, reduced fruit set, increased buttoning, and reduced fruit quality. There is still research being done to assist growers with these problems, but serious growers routinely keep track of how long there trees have been dormant with a measuring system called chilling units (CU). Beginning in November they will record the number of hours the temperature fell below 45 degrees fahrenheit, or the number of hours between 32 and 45 degrees fahrenheit to get an idea of how long there trees have been dormant. The number of chilling units needed depends upon the type and variety of tree, but this way growers can get an idea of what to expect and orchard management practices needed.