when would be the best time to start prunning them ? ....another ? is how much to prune off? --->they are in need of some help!!--
these are all nice healthy trees they are just not producing any apples. any/all suggestions are greatly appreciated-- thanks.

For our area, right about now. It is best to prune when the tree is dormant. In Vermont, the end of Feb/early March is ideal. As far as producing, try fertilizer around the drip line. It will do wonders!

. . . Rob

I've seen large trees, that have never been pruned produce excellent crops of apples, and others -pruned, produce none. Some years a tree just fails, sometimes a whole orchard. Make sure they get sufficient light, and prune out a good deal of branches - remember - only horizantal branches produce large amounts of apples.