Fertilizing fruit trees properly is essential for their healthy growth and high yield.

Knowing the best time to fertilize and using the right methods can maximize the effectiveness of the fertilizer and promote robust tree growth.

Best Time to Fertilize

Base Fertilizer

Base fertilizer is the fundamental nutrient source for fruit trees. It’s best applied in autumn, after fruit harvest and before leaf fall. At this time, the tree roots are in a peak growth phase, the soil temperature is still high, and soil microbes are active.

Applying base fertilizer allows the roots to quickly absorb nutrients, helping to restore the tree’s vitality and accumulate nutrients for the next spring’s budding, flowering, and new shoot growth. For example, applying base fertilizer to apple trees in September to October can significantly enhance their cold resistance and promote flower bud differentiation, laying a solid foundation for the next year’s high yield.

Pre-Bud Break Fertilizer

Before fruit trees start to bud in spring, it’s a crucial time to apply nitrogen fertilizer. The trees need a lot of nitrogen at this stage, and sufficient nitrogen can promote rapid new shoot growth, quick leaf expansion, and enhanced photosynthesis. Generally, apply nitrogen fertilizer 2 to 3 weeks before bud break.

For instance, applying nitrogen fertilizer to peach trees in early March can effectively increase the length of new shoots and the number of leaves, creating favorable conditions for subsequent flowering and fruit setting.

Flowering Period Fertilizer

During the flowering period, fruit trees have a high demand for phosphorus and boron. Phosphorus fertilizer can promote flower bud differentiation and pollen tube elongation, increasing fruit set rates.

Boron helps with pollengermination and fertilization. At the beginning of the flowering period, you can spray a solution of boron fertilizer and potassium dihydrogen phosphate on the leaves. This can significantly improve the pollination success rate and reduce flower and fruit drop. For example, spraying boron fertilizer on pear trees during the flowering period can increase the fruit set rate by 10% to 20%.

Fertilizing Methods

Circular Trench Fertilizing Method

Dig a circular trench outside the tree canopy projection, with a depth and width of 30 to 40 centimeters each. Apply the fertilizer evenly into the trench and then cover it with soil.

This method is suitable for young fruit trees and can guide root expansion outward. However, the position of the circular trench should be moved outward each year to avoid excessive root damage. You can use a specialized fruit tree fertilizer applicator for this purpose.

Radial Trench Fertilizing Method

With the tree trunk as the center, dig 4 to 6 radial trenches within the tree canopy projection. The trenches should be 20 to 40 centimeters deep, with the depth increasing gradually from near the trunk to the outside.

Apply the fertilizer into the trenches and then cover with soil. This method is suitable for mature fruit trees, allowing for more even fertilizer distribution and better nutrient absorption by the roots.

Trench Fertilizing Method

Dig piece-shaped trenches between or among fruit trees, with a depth and width of 30 to 50 centimeters each. Apply the fertilizer into the trenches and then cover with soil. This method is convenient for mechanized operations and is suitable for densely planted orchards. It allows for concentrated fertilization and improves fertilizer utilization efficiency.

Different stages of fruit tree growth have varying nutrient requirements. By knowing the best time to fertilize and choosing the right fertilizing method based on the actual situation of the fruit trees, you can provide sufficient and effective nutrient support for their growth.