Typically, shrubs, perennials, and trees don’t need additional fertilizer. Whereas lawns and edible gardens usually do.
Woody plants and perennials are best left undisturbed. They are “fertilized” with their own leaves and mulch. Rather than raking leaves and twigs into bags and sending them to the landfill, simply rake or blow them back to the base of those plants the way they would be in nature.
This mulch encourages the fungal activity that woody plants and perennials need, while synthetic fertilizers encourage fast, weak growth that is attractive to deer and rabbits. Slower growth, especially in trees is better for resisting wind damage. Save time and money by not fertilizing, or spraying pesticides or herbicides where they aren’t needed.
Lawns likewise don’t need chemicals but they do benefit from some additional nitrogen; rake off leaves and use a mulching lawnmower that lets the grass clippings to go back into the soil they came from. An organic fertilizer a few times a year is plenty.