The Best Fertilizers for Apple and Pear Trees

Apple Trees

The ideal soil pH for apple trees is between 6.2 and 6.5. When choosing a fertilizer, consider how much the tree grew during the previous growing season. If the plant grew less than 8 inches and the tree appears frail, put 1 lb. of a general purpose fertilizer, such as a 10-10-10 product, on the tree in early May. On other hand, just apply potash or a sulfate fertilizer during the early spring season on apple trees that did grow more than 8 inches.

The best fertilizer for pear trees is an ammonium nitrate fertilizer, which can lower the pH level of a high alkaline soil closer to the ideal of 6 to 6.5 for pear trees. Apply 1/8 lb. of the fertilizer to each pear tree, multiplied by the number of years the tree has been established. This fertilizer is appropriate only if the soil does not already have a high level of fertility. In addition, measure the amount of growth your pear tree achieved at the end of the current growing season. If the level of growth was more than 12 inches, decrease the fertilizer application level the next spring.

Avoid using products that combine lawn fertilizers with weedkillers to avoid harming an apple tree you wish to fertilize. Do not use a fertilizer containing a high amount of nitrogen on pear trees because the nitrogen can cause the tree to focus on foliage growth, making the tree appear lush but more susceptible to pests such as fire blight disease bacteria. Also, once a pear or apple tree becomes older than 4 or 5 years, use only a complete fertilizer, such as a 10-10-10 formula, on the trees, applying 2 to 3 lbs. of the fertilizer per diameter inch of the tree.

Nitrogen usually is the only chief nutrient your apple trees require each year, particularly if the soil pH is more than 7.8. Otherwise, if the pH hovers around 6.5 to 7, a 15-5-10 fertilizer should suffice. Although most fertilizers contain all of the major plant nutrients of nitrogen, potassium and phosphorus, apple trees may need an application of boron every three to four years if you notice light brown spots inside the fruit.