The reason for the appearance of frostbites is the sudden temperature drops, which are not uncommon in winter. Most often, such cracks appear on fruit trees: apple trees, cherries, sweet cherries, plums, pears.
It is important to remember that under the influence of frost, wood deforms along the radius and in the perpendicular direction. This causes tissue rupture. In addition, a temperature difference arises in the center of the tree and at the periphery, that is, the outer layer is compressed more, which also causes cracks..
Walking through the forest in frosty weather, you can hear the characteristic crackling sound. This is the first sign of frost cracks. The cracks themselves do not appear on the bark immediately, usually gardeners notice them only in summer. Internal damage could have appeared last winter, but the bark was hiding them. The next winter, damage to tree tissue intensifies and, as a result, the frostbite becomes a noticeable violation of the integrity of the trunk..
Like all diseases, frost cracks are easier to prevent, to carry out prevention, than to treat already obvious problems. Yes, at best, the crack can overgrow itself – the cambium begins to develop with the onset of heat, the tree heals. But it is better not to hope for such a most favorable outcome, most often frost holes only increase with each winter, and over time they completely turn into hollows.
The most effective means of preventing frost damage are:
- Autumn whitewashing of trunks and lower branches. We have already written about the benefits of the usual whitewashing of trees. Among other things, this is an easy way to help the tree cope with the temperature extremes in winter and avoid frost damage. It is important to whitewash in autumn, and on sunny winter days, check the condition of the applied layer and, if necessary, update it;
- Wrapping tree trunks for frost protection. Burlap, spruce branches, thick paper or just newspapers, special covering materials are perfect – it is strictly not recommended to use only polyethylene. The material with which you protect the tree trunk must “breathe”. It is important to wrap not just the trunk, but also the junctions of the lower branches – frost holes often appear here too;
- When choosing fruit trees for your garden, you should pay attention to frost-resistant varieties, and for planting choose areas where there is less cold north wind.
If it was not possible to prevent the appearance of frost, you will have to deal with treatment. In no case should you start the situation, as we already wrote, next winter the tree will only get worse. It is advisable to start the treatment process immediately, in the spring, or after you have discovered the appearance of a crack. Treatment includes the following steps:
- The first step is to cleanse the wound from already dead wood. You will need a sharp garden knife, a scraper, and a metal brush. Remember that healthy wood is dense and light – you need to clean it before it.
- A cleaned crack must be treated with a 5% solution of copper sulfate. This will kill all fungi and microorganisms that could have time to get under the damaged bark..
- The treated wound should be covered with clay or garden varnish, which can be made with your own hands on the basis of paraffin, beeswax, with the addition of turpentine, pine resin. There are a lot of garden recipes, there are also ready-made compositions that can be bought in specialized stores.
- After applying clay or garden varnish, the crack can be simply painted over. However, if the damage is large, you will have to make the harness with burlap, which is pulled together with wire around the trunk. As they bandage rather serious wounds on the human body, so a tree in this case will need a bandage.
Be prepared for a long time to heal the frostbite. You will have to repeat the entire treatment process described by us both next spring and a year later. If the tree cannot recover, there are two options – grafting new branches onto a cut trunk or a cardinal method – uprooting and planting a new tree. We sincerely hope that thanks to our advice it will not come to this.