Why a tree is frozen, causes
There are several reasons:
Dramatic temperature changes in winter;
severe frosts in early autumn, when there is still no snow;
mistakes of gardeners in preparing the garden for winter.
Most fruit plants usually feel well at temperatures down to minus 25 ° C, and winter-hardy varieties can even withstand minus 35 ° C. But here in Kuban, there can be no such strong frosts, but trees still get frosty…
This was the case with one of my pears a few years ago. I ordered in an online store. The seedling was sent late – at the end of November. But here in November-December most of the time the weather is relatively warm and it is quite possible to plant a sapling. So I did, but on the third day after planting at night there was a frost of minus 10°C. It seems to be a small frost, but it hit the thin branches of the seedling, which did not have time to root. In the spring, I was disappointed to see that the buds had not awakened. I did not dig out the tree. A little later I saw a live shoot just above the grafting site.
I cut off the non-living part of the seedling. It was almost the whole trunk. A new shoot began to grow at an angle of 45 degrees. So that the future tree did not turn out crooked, I stuck a peg from the opposite side of the young shoot and carefully gave the shoot an upright position. Now it is not even noticeable that once it was not the trunk, but a separate branch growing sideways.
This pear is still growing on my plot. This season gave the first harvest – 1 fruit. But I am immensely happy and one pear – large and delicious. Most importantly, I managed to save the tree, but, of course, the harvest had to wait for an extra 2 years.
How to check whether a tree is frozen or not
If you suspect that a tree has not survived the winter well, cut a few twigs off and place them in a glass of water in a warm place covered with a plastic bag. If the flower buds are swollen and light green when cut, the tree is probably okay.
Then, after waiting for the leaf buds to begin to awaken, make a longitudinal cut into the branch and look at the color of the wood. A healthy branch will have white or slightly greenish wood. Weakly frosted one acquires yellowish tint, with severe damage it will be light or dark brown, sometimes even brown, dead cambium – the same color.
If frost damage is detected, then pruning will be the salvation for the tree. But you should not rush with such treatment, it is necessary to wait until the surviving parts of the tree come out of wintering. Keep in mind, however, that frozen buds blossom later. While you are waiting for the tree to wake up, make sure you treat it for diseases and pests, otherwise they will weaken it even more.
It happens that both flower buds opened and leaves began to unfold, and then everything sharply withers.
In this case, the root system is most likely affected. Dig up a few roots and check them on the cut: brown color is an indicator of death. If the tree is severely frosted, it will have to be uprooted.
The buds that have blossomed will show the extent of damage to the tree. If last year’s growth or its tops are frozen, simply cut out the withered parts to healthy tissue.
How to prune frozen trees, what to treat with
If the wood of the skeletal branches is affected, shorten them to the place where the active growth of shoots began. If the tree is severely damaged, your job is to save the most of the live wood. By the beginning of summer, unrecovered branches will show up, they may even have flowers on them, as well as small bumpy leaves. Such parts should be removed so that there is a chance to save the tree by cutting them into a ring. Otherwise, on top of all the troubles, woodworms, bark beetles and other pests will appear.
Removal of skeletal branches to 3-4 year old wood, rationing the harvest by half or more (after natural wilt shedding) will allow the tree to recover. At the same time, the plant will be weakened for another couple of years.
After pruning, all wounds should be immediately covered with garden varnish. In the absence of rains, watering and feeding are necessary, as well as constant treatment against diseases and pests. Add Epin or Zircon to the tank mixture (according to the instructions).
If the frost has gripped almost the entire tree, but the grafting site is preserved, the young growth will be varietal and from it you can try to form a new tree in the form of a bowl or bush.
The root circle of the affected tree should be carefully loosened and mulched, treating the mulch with Baikal or another similar preparation.
Important: Treatment of branch cuts is carried out with copper sulfate diluted in water (100 g per 10 liters of water). After disinfection, this place is covered with a garden varnish, which will avoid the entry of infection.
Prevention of freezing
As a rule, old, weakened trees or young seedlings are subject to frost. To avoid all kinds of unpleasant surprises, to avoid fruit-tree diseases, it is necessary to prepare your garden for wintering in advance by stopping nitrogen fertilization in the middle of August, treating plants against diseases and pests throughout the season, not overlooking the reproduction of aphids on the ends of young shoots closer to autumn and in warm autumn weather.
It is imperative to do moisture watering, even if it rains. Small rains will soak only 10-15 cm of soil, but the roots lie much deeper!
Mulch should be mulched, because in warm winters, it is the root system that suffers most often.
Trunks and scaffold branches should be whitewashed from autumn. Whitewashing trees for the winter will help to avoid sunburns and the action of drying winds. By the way, the same role of protecting trunks from burns and frostbites will be played by a garden bandage. It is very convenient – it stays on the tree for at least two seasons, it does not require renewal after rains and strong winds.
Young plants planted in the current year and 2-3 years ago, it is best to bandage with burlap to protect against frostbite and nibbling by hares, mice and other pests.
It is easier to prevent than to treat!