GardenLine | Fruit to Grow and Pick | Fall Is The Time To Protect Orchard Areas Before Winter Sets In

There are a number of precautions you can take to protect your orchard. Young fruit trees on the prairies are particularly vulnerable to winter damage from sunscald and the hungry mouths of rodents, deer and rabbits. Although you can not protect the trees from the real world of -40C, you can give them some help.

The real world of the Canadian Prairies is very cold in the winter with very dry air and plenty of wind. All of these conditions make living for a young tree very hard. Another weather condition which is very hard on your trees occurs in March. In the spring of the year, while the roots of plants are solidly frozen, the bright sun shining on the bark of the tree can warm the tissues to a temperature of 20C. The warmed tissue become active and unable to take the night time temperature of -20C. As a result the cells die and bark becomes discoloured leaving the tree with only part of its conducting tissue. The condition is called sunscald and occurs on the south and west sides of the tree. Some trees due from their injury, other struggle along and do poorly. You can help protect your tree by using white plastic tree guards which reflect the heat of the sun, and the tree remains inactive until the �real� spring weather comes. These devices are available from garden suppliers and are usually put on in late fall.

Other activities which may help include the use of white latex paint on the south and west sides of the trunk, or the leaning of boards against the tree to help shade the trunk during the month of March. People have also used aluminium foil (shiny side out) to shade the trunk at this time of year. The foil can be removed in the spring and reused next year.

The control of sunscald using the foil or the tree guards also is effective in controlling another winter problem, that of mouse damage. Mice often become very hungry when winter snow hides their food, and young tree bark becomes a tasty alternative to grain or weed seeds. In this case the plant guards and foil prevent the mice from stripping the bark away. Another good control is a heavy hardware wire mesh which prevents mice from getting to the trunk of the tree. Mice usually only eat below the snow line and do not climb over the mesh.

Cultural practices related to growing fruit trees can also influence the abundance of mice and hence mice damage. Leaving uncut grass or other cover in the area will encourage mice, on the other hand low cut grass and clean clean cultivation will discourage mice and reduce or eliminate a mouse problem. Commercial people will often use a bait station to kill mice and reduce the problem. A bait station should allow mice in to eat the bait, but be both child and pet proof.

Note: Mice can be very destructive and in bad years can kill out most of an orchard. Repairing mouse damage is difficult and costly on tree fruits, you must, however, repair tree fruits or death occurs.

Bush fruits are usually not killed by mice even though they may have been severely damaged. They are difficult to repair and are usually left to send up new shoots from below the damaged area. As a result you must wait several more years for fruiting to occur.

Mice damage can occur in the city or farm, deer and rabbit damage usually occurs only in the country. Both can be controlled by a high (6') mesh fence. The fence must be high enough to keep deer from jumping in and with small enough sections to prevent rabbits from entering.

Deer can be a problem throughout the year, feeding on leaves and new growth in the summer and shortening back the ends of branches in the winter. Deer have also been known to damage strawberries in the winter as they remove the straw cover and eat the strawberry leaves. Removing the straw can destroy the insulation value of the straw and cold damage results.

Rabbits usually only damage trees and bush fruits in the winter. The damage may be removal of twigs or the stripping of bark on the trunk or branches. Bark that has been stripped can be repaired, however, it is very time consuming.

You might discourage deer and rabbits from entering your orchard by spreading blood meal. The meal offends the animals and they tend to stay away. When food supplies are low the meal does not work.

Watch for porcupines, they may attack your trees in the winter months. They tend to live on the bark of trees and fruit trees are one of their favourites. There is little you can do except remove them from the area as they will come back nightly and eventually your tree is ruined.

Protect Your Fruit Trees in the Fall from damage during the winter and early spring. Dry air and brisk winds during winter are especially damaging to young fruit trees.

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Sustainable horticultural information, offered free of charge to the public with the support of the University of Saskatchewan Extension Division, the Department of Plant Sciences and the Provincial Government.