How to Fertilize Hawthorn Trees? Master These Key Fertilization Points

The main fertilization periods for hawthorn are base fertilizer, flowering-stage topdressing, early fruit-swelling stage topdressing, and fruit-swelling stage topdressing.

Base fertilizer application. It is best carried out promptly in late autumn after the fruit is harvested, as this promotes the tree's absorption and accumulation of nutrients and benefits flower bud differentiation. The base fertilizer should preferably be mainly organic fertilizer, combined with a certain amount of chemical fertilizer. The amounts of chemical fertilizer are as follows: nitrogen fertilizer used as base fertilizer generally accounts for about half of the annual application rate, equivalent to 0.25 kg to 1.0 kg of urea or 0.7 kg to 5.0 kg of ammonium bicarbonate; phosphorus fertilizer is generally mainly used as base fertilizer, accounting for about 80% of the annual application rate, equivalent to 1.0 kg to 5.0 kg of superphosphate containing 16% phosphorus pentoxide. The amount of potassium fertilizer in the base fertilizer is generally mainly 0.25 kg to 2.0 kg of potassium sulfate or 0.25 kg to 1.5 kg of potassium chloride. The application rate is determined according to the size of the fruit tree and the yield of hawthorn. Dig a 20 cm to 40 cm trench and apply it in, taking care not to get too close to the tree; first mix the chemical fertilizer moderately with organic fertilizer or soil before applying it into the trench, to avoid burning the roots.

Flowering-stage topdressing. Mainly nitrogen fertilizer, generally about 25% of the annual application rate, equivalent to 0.1 kg to 0.5 kg of urea or 0.3 kg to 1.3 kg of ammonium bicarbonate per tree. According to actual conditions, an appropriate amount of phosphorus and potassium fertilizer can also be applied as a supplement. Apply it in small trenches combined with irrigation.

Early fruit-swelling stage topdressing. This is mainly to improve nutritional conditions for the early stage of flower bud differentiation, and is generally managed flexibly according to soil fertility conditions and the situation of base fertilizer and flowering-stage topdressing. If the soil is relatively fertile and plenty of base fertilizer and flowering-stage topdressing have been applied, it may be omitted or applied sparingly; if the soil is relatively poor and little or no base fertilizer and flowering-stage topdressing have been applied, appropriate topdressing should be carried out. The application rate is generally 0.1 kg to 0.4 kg of urea or 0.3 kg to 1.0 kg of ammonium bicarbonate per tree.

Fruit-swelling stage topdressing. Mainly potassium fertilizer, combined with a certain amount of nitrogen and phosphorus fertilizer, mainly to promote fruit growth, increase the carbohydrate content of hawthorn, raise yield, and improve quality. The amount of potassium fertilizer per fruit tree is generally 0.2 kg to 0.5 kg of potassium sulfate, combined with 0.25 kg to 0.5 kg of ammonium bicarbonate and 0.5 kg to 1.0 kg of superphosphate.

Hawthorn has a relatively low demand for trace element fertilizers and mainly relies on organic fertilizer and soil to provide them. If plenty of organic fertilizer is applied, trace element fertilizers may be omitted or applied sparingly; if little organic fertilizer is applied, trace element fertilizers may be applied appropriately. The actual amount of micro-fertilizer is calculated by the specific fertilizer and applied as base fertilizer: borax at 0.25 kg to 0.5 kg per mu, zinc sulfate at 2 kg to 4 kg per mu, manganese sulfate at 1 kg to 2 kg per mu, and ferrous sulfate at 5 kg to 10 kg per mu (it should be applied together with high-quality organic fertilizer, with a ratio of organic fertilizer to iron fertilizer of 5:1). Micro-fertilizers can also be sprayed on the leaves, with the spray concentration controlled at 0.1% to 0.5% according to the degree of leaf aging; it should be more dilute when the leaves are young and can be somewhat more concentrated when the leaves are older.