In the modern production technology, the foliar fertilization of potatoes is one of factors determining the yield, its quality and durability. Traditional foliar fertilization does not always guarantee the availability of the necessary nutrients to obtain a high yield of good quality. A low pH of the soil with humus deficiency, a lack or excess of precipitation during the vegetative period and also absence of necessary micronutrients restrict and inhibit the uptake of nutrients by roots. Potatoes take up macronutrients in relatively high amounts: potassium (K2O) – 6 kg; nitrogen (N) – 5 kg; phosphorus (P2O5) – 1.5 kg; magnesium (MgO) – 0.7 kg; sulphur (S) – 0.6 kg; calcium (CaO) – 0.6 kg per 1 ton of tubers and micronutrients in very small amounts: iron (Fe) – 43 g; manganese (Mn) – 7.7 g; zinc (Zn) – 7.5 g; copper (Cu) – 2.2 g; boron (B) – 2.7 g; molybdenum (Mo) – 0.1 g per 1 ton of tubers, which, however, are necessary for proper development and yields. Potato plants are very sensitive to manganese and zinc deficiencies and their lower amounts as compared to other micronutrients. For potato plants, a high demand for nutrients begins as early as in the tuberization period, i.e. when tubers are formed on stolons, the most intensive nutrient uptake occurs when the tuber mass increases. Potatoes do not like freshly limed soils as tubers can be attacked by potato scab with greater intensity. Foliar fertilization can increase the yield by as much as several dozen percent! Better nutrient uptake by leaves is promoted by high air humidity and temperatures of 12-15°C. However, no treatments should be performed when the temperature exceeds 20°C, as this might damage leaf blades. The optimal time of the day is late afternoon or early morning at temperatures of 12-15°C and high air humidity. The recommended dose of the preparation dissolved in 300 litres of water should be applied. The temperature of water used for the treatment should range from 15 to 20°C. Cold water can cause burns upon contact with warm plants. Moreover, low water temperatures make it difficult to dissolve and mix the preparation. Treatments performed after rain are also effective, right after the plants have dried and the soil humidity allows for the treatment. Macro- and micronutrients contained in foliar fertilizers permeate to plant tissues through the epidermis and stomata on the leaves and shoots. Young leaves absorb the most micronutrients, especially their lower parts where the largest number of stomata are situated. Large doses of nitrogen increase the tendency to darken and to develop internal spotting. Susceptibility to growth cracks and pink rot also increases. Foliar feeding with phosphorus accelerates plant maturation, increases the yield and reduces mechanical damage. The use of potassium increases the effectiveness of photosynthesis and respiration, reduces losses caused by diseases during storage. The use of magnesium sulphate heptahydrate brings very good results in soils with low and medium richness in magnesium. Magnesium facilitates nitrogen uptake and prevents potential burns; it is also responsible for the photosynthesis process and starch accumulation. Compound fertilizers containing both macro- and micronutrients play a growing role in foliar feeding. Nutrients should be provided to potatoes especially during tuber formation when the demand for them is the greatest. For the majority of cultivars, this takes place in June and July. The first foliar treatment is usually applied two weeks before flowering. The last treatment should take place when green berries appear on the plants. Deficiencies of some micronutrients are observed more and more frequently in very intensive potato cultivations. The best and the most effective method is the use of one of numerous foliar fertilizers with a higher content of individual micronutrients or one ingredient. To increase the efficiency of foliar fertilization, micronutrient fertilizers are enriched with nitrogen and sometimes potassium and magnesium. An addition of 6-10% of urea solution is recommended with a low nitrogen content in micronutrient fertilizers or low doses of soil fertilization. The foliar fertilization of potatoes improves tuber quality and storage durability and helps reduce the content of harmful nitrates. Economic effects of higher potato yields obtained as a result of foliar fertilization with microelements are very high and many times exceed the costs incurred for the purchase of fertilizers and mechanical spraying treatments.