Correct Fertilizer Rates for Mature Apple Trees

Fertilizing 15-Year-Old Apple Trees

The recommended rate for a 15-year-old apple tree is 7.5 lbs of 10-6-4 fertilizer, broadcast under the drip line and watered in. This amount is correct and not excessive for a mature, bearing tree.

Best Practices

• Apply before rain to avoid manual watering.
• Conduct soil tests every 2–3 years to adjust rates.
• Prune annually for optimal growth and fruit quality. See OSU pruning guide.

Key Takeaway

Mature apple trees need substantial nutrients. Follow soil-test-based recommendations and pair fertilization with proper pruning.