Every spring and fall there us an opportunity to fertilize the trees. We suspect our trees are deficient in nitrogen and spraying fish guts can help correct that, as well as deposit a broad spectrum of micronutrients and elements such as zinc, phosphorus, and calcium. We like to spray the fish guts, lets the leaves absorb the food, reassess and apply as needed, but the rule is no nitrogen after July. The trees need time to go dormant. If you keep fertilizing the trees keep growing and don’t transition well going into winter. Fish guts over chemical fertilizer any day! It smells amazing!