When is it too late to feed apple trees?

Many orchard owners use the summer solstice (June 21) as the cutoff date, but others say July 1. The reason is that fertilizing the trees too late in the season can cause confusion when it comes time for them to go dormant. And if their dormancy is delayed, especially in more northern climates, they may be caught off guard by the coming of winter or even an early fall frost. Late feedings also cause late-summer growth, which will prove particularly susceptible to the coming cold. If you want to do something for your trees after the deadline, remove any grass and weeds that might be crowding them and spread a good layer of mulch outward for about four feet. Hay, grass clippings, wood shavings, shredded bark, and other organic materials are all good choices and will enrich the soil.