when do I spray my fruit trees

I first spray my nectarines, peaches, cherries and pears with lime sulphur the last week in July. Fruit trees need to be sprayed at bud swell which happens as the weather starts to get warmer, generally in August. I spray the last week in July and again about mid August depending on how the buds are swelling in aim to spray at the right time which is just before they split. Some apples can not be sprayed with lime so I spray them with a copper spray.