My little apple orchard

Nice looking trees. I put in a Honeycrisp this year that I purchased from Meijer. It had flowers going up and down the branches and trunk, but it's way too young to be producing fruit. I need the nutrients to go into tree growth. Give your Jonathan some time, it's still young.
I had a little dieback on the top of a Zestar from Stark's that I put in two years ago. I thought it might be Fireblight, but now think it is a disease called Nectria Twig Blight, which is a fungus as opposed to a bacterium. I pruned off the necrotic part and so far so good. Don't tell anyone, but I also put in a Red Haven peach just to see if I could get it to grow here. Two years ago the winter took it back to about a foot off the ground. Last year it put off a spike that made it through last year's milder winter. This spring all the branches are leafing out nicely. I'm wondering how this next winter will treat it!

Oh yes, keep the water to that new Honeycrisp's root until it's established well.

Beware, those are like crack to bambi.

Yup, the heat right now is pretty hard on things. The compost is a great idea. I've found that the tree spike fertilizer for fruit trees seems to work well, but that's the synthetic vs. organic argument which I like to come down on the side of natural if I can.
As far as pruning, you would probably get 10 different answers from 10 different people. It's sort of a scientific artwork. When apple trees are young, I was taught to whip them back. Meaning you leave a central leader (main stem) and 3-5 lateral branches. These lateral branches are best to have between a 45-90 degree angle to the main trunck because as they grow and add the weight of the apples to the branch, people have found that to be the strongest bond to the tree. Also, you want them spaced around the stem to all sides and a bit of separation vertically in where they attach to the main leader. By whipping back, I was taught to pick a bud on the lateral shoots that is in good shape and aiming in the direction that you want that branch to extend out into. Clip the branch just past that bud and let the next seasons growth start. I find it best to do this a day or two before any rain storms as water on fresh cuts can spread diseases. The central leader can be cut at a bud that again, is on the side of the stem that you want the leader to lean towards (usually the prevailing wind direction). I would make that cut at about 5 feet up on a young tree. The tree on the lower right of your photo looks pretty good with the lateral branches forming well. Later on a second set of laterals will likely develop a few feet higher on the tree and you can work with them in a similar fashion. There are varieties that don't work best with a central leader system and I'm not sure about Honeycrisp. Mine is very tall and whip-like on the stem and branches. I'm still trying to decide how to shape it. You may want to consult an online university extension bulletin for the different styles. MSU would likely have some available. Clear as mud?

Those look like tent catipillars. They really seem to like fruit trees but are very destructive to the leaves. Look around for a white silky mass on any surrounding trees that is the source of them. They usually don't kill a tree but they certainly don't help it either.

Dave, I was spraying the apple trees this morning. All that time and I think I saw 3 apples total. Some of those really hard freezes robbed us of apples this year. The peaches are looking good but maybe less than half of what was there last year except for one tree which we've been thinking of cutting down because it just has not been a producer. We got a fair crop last year and this year looks even better. Maybe the threat was enough!

Nice trees Dave. What I do under my fruit trees is plant some garlic, garlic chives or mint. it helps to keep pest away from the trunk and climbing up to the fruit and leaves.