Best Fertilizer For Fruit Trees? Tested Boosters Compared... See The Winner When we first discovered Farmer's Secret Fruit Tree Booster, we were intrigued by its super-concentrated, phosphorus-rich formula——designed to nourish even the pickiest fruit trees. We mixed it according to instructions and applied it to our peach, banana, and apple trees, noting the immediate absorption. Within weeks, our plants showed stronger, greener foliage, and flowering improved noticeably. The 32oz bottle lasts a long time, making it cost-effective for large gardens. While we’ve tried other boosters, Farmer's Secret stands out for its targeted nutrient balance and versatility. No sudden chemical spikes—just steady, healthy growth. Balanced and reliable, it’s the winner in our quest for the best fruit tree fertilizer.