Hi I'm Tricia an organic gardener. Apricots, pluots and cherries all prefer to be pruned in the summer they also have one other thing in common and that's that they like to be trained into a modified central leader system and you're apples and pears will benefit from this too. Modified central leader systems need less space than the open vase system but more space than the regular central leader system. Apples, cherries, apricots and pears are often trained using the central modified system and for those of you in the southwest this is the best way to train most of your trees.
Between mid June and mid July is a great time to start to train your modified central leader tree and the first step is to choose four permanent scaffolding branches. The first scaffolding branch should measure eighteen to twenty four inches from the ground look for branches that are coming off the trunk at a forty five to sixty degree angle branches that have an angle to the trunk of less than forty five degrees are often week and will break under the load of fruit or snow. Each of the four scaffolding branches should be on a different quadrant of the tree and one scaffolding branch should never be directly on top of another ideally the scaffolding branches should have eight to ten inches vertically between them and don't worry if you can find all of your scaffolding branches in one season. If you have a well spaced branch but it's less than forty five degrees you can open it up and train it with a spreader.
To make a spreader you'll need a piece of wood cut to the proper length and to two ten box nails, a wire cutter, a file and a hammer. Pound one nail into each side of the wood cut off the heads of the nails then sharpen the ends of the mails a bit with the file to make them pointy then place the spreader so it fits snugly between the branch and the trunk and holds the branch at the desired angle. For very small branches a clothes pin makes a great spreader, now that i've selected my scaffolding branches Im going to label them with a ribbon so that i don't accidentally cut them off. Now i'm gonna prune back other non scaffolding branches to about six inches or to the first set of leaves this is called the trashy trunk system these short laterals will be removed later but for now they help shade the truck and prevent sun scald.
This tree was headed back at planting time and as you can see it has several competing leader shoots i need to pick the strongest upright shoot to be the leader and then Im going to cut the rest. The central leaders should be pruned about twenty inches from the top most scaffolding branch. Cutting the central leader is going to stimulate the growth of additional scaffolding branches. I want one more tier of scaffold branches to develop so i have a ideally five to seven when i have all the scaffold branches i need on this tree i'll cut the leader back to the tallest scaffold branch. Now i'm going to head back the scaffolding branches to an outward facing branch. Now i'm going to leave little shoots like this because they'll likely bear fruit. Your summer pruning will go a lot easier if you have a plan so prune your trees grow organic for life!