Basic Fertilization

• Fertilize fruit trees with up to 1 lb. of 10-10-10 fertilizer per inch of trunk diameter. Apply a maximum of 2 1/2 lbs. of 10-10-10 fertilizer per tree. Measure the diameter of the trunk 1 foot above the ground. Apply fertilizer about one month before the trees start to produce new growth in the spring. Broadcast it evenly within the area covered by the crown of each tree, but not within 12 inches of their trunks.
  
  

Planting

• Never apply fertilizer to the hole when planting young fruit trees. Give 1/2 lb. of balanced 10-10-10 fertilizer to each tree three weeks after planting. Apply in a circle at least 18 inches from the trunk.
  
  

Micronutrients

• Fruit trees require micronutrients as well as nitrogen to produce a good crop. These can be supplied in spring just as new growth starts to appear. Apply 2/3 lb. of calcium nitrate per inch of trunk diameter to each tree, spreading it within the area covered by the crown. Give a maximum of 1 3/4 lbs. of calcium nitrate per tree. Also apply sulfate of potash-magnesia at 1/2 lb. per inch of trunk diameter, up to a maximum of 1 1/4 lbs. per tree.
  
  

Soil Tests

• The exact nutrient requirements of fruit trees depend on the type of tree and the soil it is growing in. A laboratory soil test will give exact information about the quality of your soil. This is important as overfertilization can cause branch breakage, excessive leaf growth and poor fruit ripening. Trees grown in soil that is deficient in a specific micronutrient will also suffer from lower yields or poor fruit. Iron-deficient trees, for example, often produce few fruits with poor flavor.