If you want to make your plants more cold-resistant and thus fit for the winter, you should start giving them fertilizer with a high potassium content as early as autumn.
Potassium and its effects
The reason is very simple: Potassium accumulates in the vacuoles and increases the s alt content of the cell juices. Due to the increased s alt concentration, the plant is no longer so susceptible to frost. The freezing point is lowered. But that's not all. At the same time, the juice pressure in the roots is increased. As a result, both gas exchange and water transport are improved. The function of the so-called stomata of the leaves is also improved. This allows more water to evaporate and allows more carbon dioxide to enter the plant's tissues for photosynthesis.
Don't fertilize all plants
However, you should not fertilize all your plants with a fertilizer that is high in potassium. You should only provide such a potassium fertilizer to plants that are also susceptible to frost. Plants that could have problems from a temperature of -5 degrees should be fertilized to be on the safe side. The lawn will also gratefully accept potassium fertilization. Older plants in particular do not naturally have as much potassium as young plants. It is therefore very important for older plants that you supply them with sufficient potassium in winter.