Enhancing the frost resistance of fruit and berry crops and their preparation for wintering

Successful wintering of fruit and berry crops is the foundation of a high yield in the following season. Autumn is a critically important period for plants to accumulate reserve substances, strengthen cell walls, and increase overall frost resistance. A balanced mineral nutrition plays a key role in this process, ensuring proper preparation for temperature drops.

Properly planned autumn fertilization is aimed not at stimulating growth (as in spring), but at directing the plant’s energy towards flower bud formation, sugar accumulation, and removal of excess moisture from cells.

Soil Fertilization

In autumn, the focus completely shifts to phosphorus and potassium. Nitrogen, on the contrary, should be excluded or minimized, as it provokes continued vegetation growth — causing plants not to mature before frost and thus become vulnerable to low temperatures.

POTASSIUM – “The Element of Winter Hardiness”
It is the most important element of autumn nutrition, as it performs a number of key functions in preparing plants for winter, namely:

• increases the concentration of cell sap, promoting the outflow of free water from cells and thereby increasing the frost resistance of crops;

• stimulates the transfer of assimilates from leaves to perennial wood, buds, and the root system. The sugars accumulated in this way act as a natural antifreeze;

• promotes better wood maturation, making it stronger and more resistant to cracking during freezing.

Among potassium fertilizers, Makosh Kalium is used during this period.

PHOSPHORUS – “The Element of Energy”
It is essential for the accumulation of energy required for all physiological processes involved in preparing plants for the winter period, namely:

– promotes the intensive accumulation of ATP (adenosine triphosphate), which will be used in early spring to initiate vegetation;
– supports the development and preparation of the root system for wintering.

Recommended phosphorus fertilizers include Makosh Fosfat or complex fertilizers such as Makosh 18+B, Zn; NPK 7:21:21 +S +Zn, and Makosh NPK 5:13:13.

Approximate application rates:
Apply in September – early October, within the trunk zone.

• Phosphorus (P₂O₅): 25–40 kg/ha a.i.

• Potassium (K₂O): 60–90 kg/ha a.i.

2. Foliar Fertilization

Foliar fertilization is a rapid-response tool, as it helps supply nutrients to plants quickly for immediate mobilization — which is especially important in autumn.

– Potassium.
Late autumn spraying with potassium fertilizers (2–3% concentration) is the most effective measure for accelerating shoot maturation and increasing sugar concentration in plants.

For potassium feeding, use Potassium sulfate, Monopotassium phosphate, or the complex fertilizer Makosh 10-20-30.

– Phosphorus.
During autumn foliar feeding, phosphorus provides plants with the energy necessary for carbohydrate (sugar) translocation from leaves to perennial wood and buds. This sugar accumulation acts as a natural antifreeze, critically increasing frost resistance and contributing to quality flower bud formation for the next year. Use Makosh 10-53-10.

– Magnesium and Sulfur are also very important elements for autumn feeding. They are often applied together in a tank mix with other phosphorus-potassium fertilizers.

Magnesium, even in autumn, continues to support active photosynthesis (even at lower temperatures), which is necessary for carbohydrate accumulation.

Sulfur improves nutrient absorption and promotes protein accumulation, which will be needed for successful wintering and early spring vegetation. For magnesium and sulfur feeding, use Magnesium sulfate at 5–10 kg/ha.

– Boron plays a critically important role in sugar transport and strengthening of cell walls, making them more elastic and resistant to mechanical damage caused by freezing and ice crystal formation inside the cells (Makosh B 11, 1–2 L/ha).

– Zinc is an important element for improving the winter hardiness of fruit and berry crops. It participates in the synthesis of auxins (growth hormones) and tryptophan, accelerating shoot maturation and ensuring the rapid outflow of assimilates (sugars) from leaves to perennial wood. This leads to the accumulation of natural “antifreezes” in cells, significantly enhancing frost resistance.

Use Makosh Zn-8 at 1–2 L/ha.

Foliar fertilization should be carried out in September–October, 3–4 weeks before leaf fall.

Conclusion

A comprehensive approach to autumn nutrition — combining soil and foliar applications — enables fruit and berry crops to effectively undergo the hardening process. This not only increases their direct resistance to winter frosts but also ensures a strong start and high productivity in spring.

Investment in autumn fertilization is an investment in next year’s harvest.