I use dormant oil for our fruit trees.............apply fall and then again in the spring spray in the spring until the flower opens..........once opened do not spray the flower spray very early on the trunk under the branches to the ground. We need bees to polunate the trees. If you spray after the flowers open you will kill the bees. It is available at Walmart, must follow the measurements on the container............also sold at Lowes and Home Depot.