Harsh winters and frost in autumn or spring can have severe effects on fruit trees from regions with mild winters, such as quinces and peaches. Sudden cold snaps cause great damage, especially in spring. Not only the fruit tree blossom is endangered, but also the bark of the trees. These can crack and thus offer pathogens a gateway.
Lime protects fruit trees from frost damage
Why and how you should lime fruit tree trunks
From mid-January, but no later than February, the tree trunks on the south side begin to warm up on sunny days, while the temperatures drop sharply on the clear nights that follow. This creates tension in the bark tissue, which ultimately leads to frost cracks. So-called frost plates - where parts of the bark tissue dry out - are also the result of strong sunlight and extreme temperature fluctuations. To protect the fruit trees from this damage, paint them with a lime solution as a preventive measure. You can add some wallpaper paste to this for better adhesion or buy a ready-made lime or white coat from a specialist shop. Incidentally, such a lime coat does not protect against pest infestation or deer browsing, it only reflects the sun's rays.
How to recognize frost and cold damage
Typical frost damage is cracks in the bark on trunks and branches, which in severe cases form deep crevices or flake off like plates. You also recognize frost damage:
- shoot tips turning dark brown to blackish
- dead shoot tips
- Plants dead due to frozen roots
- discoloring leaves (yellow, reddish, sometimes also brown to black)
- buds and flowers turning brown
- Fruits with brown, black, russet or glassy parts, longitudinal cracks or rings in the calyx region
In such cases, you usually only have the option of cutting off the affected parts or even clearing the entire tree. In spring, simply cut back fruit trees that regenerate through new growth until the healthy wood has grown.
This also prevents frost damage
In addition to a lime coat, you can also protect your fruit trees from frost damage with the following measures:
- Preferably choose south-east, south-west or bright east faces for trellis fruit, no sunny south faces.
- For freshly planted and sensitive trees, cover the root area as well as the trunk and shoot base with leaves and/or spruce sticks.
- Place potted plants that overwinter outside on insulating Styrofoam plates or boards.
- Make sure you have a sufficient supply of potassium, as this increases winter hardiness.
- Do not use nitrogen-rich fertilization in late summer.
- Do not cut fruit trees when the temperature is below minus five degrees Celsius.
tips
If you ever forget to whitewash, put a board on the south side of each tree trunk. This also keeps the sun's rays out.