Other than the old bromide "natural variation" I can't explain it. However, try documenting a few trees with photos, and track them in the fall. Then do it again the following year. That will at least indicate whether this is a transient effect or if it may be due to permanent characteristics of those trees.

Thanks! This plan is being inspired by an issue similar to the "America Elm". The road used to be planted with Black Pine, which were very salt tolerant. An epidemic of bark beetles wiped them all out. Interestingly, I had been looking for salt tolerant evergreen replacements before, and never ran into the name pinus radiata. I'd be worried the bark beetles would take them out. Eastern White Pine is IMHO the prettiest pine and totally immune to the local diseases, but particularly vulnerable to salt. That's what the neighbors planted. Ended up using pitch pine, which is very salt tolerant, but still might have some beetle vulnerability. Also considered Atlas Cedar. There are a lot of wild Juniperus virginiana thriving on the sight. Euonymousis an invasive species here. I did consider sea buckthorn for erosion control on another spot. While it isn't considered invasive in my area, I'm told some are worried it will be. I'll have to look into Holly Oak...it should survive here. It's rated for my zone. Tupelo is a tree I really think is in theory perfect for the area. Very wind resistant, slightly salt resistant, beautiful fall color, not particularly susceptibility to local diseases. The catch is this is for my parent's property...I won't be there to water them. I can't find a cheap source of tupelo, and I hear it doesn't take well to transplanting. So my "plant a bunch and hope some survive neglect" strategy likely won't work for it. I'm waiting until I can get my parents more interested in the project to plant a couple tupelo in the "place of honor" where they can be seen from the house. At the moment, I'm looking for a row of cheap bare root things I can plant in a row along the road in front of the field. This part of the project is deciduous because I want to keep the Fall color of the area and not completely obstruct the neighbor's view.

Your problem sounds more complicated than what you describe. More information and adding some pictures would help those reading this visualize the situation. Have you been watering the tree up until you worked on the mulch problem? Working on a stressed tree where you might have broken surface roots with the rake could explain the wilting. How much top soil did you add to the surface of the mound? It would take more than a couple inches of dirt to smother roots imo. How deep is the mulch? You only need 2-3" on top, to protect the soil from the hot sun and hold moisture. I personally would be hesitant using freshly ground mulch, unless I knew it was completely dead wood and bark. Heaping stuff on that contains green or sap wood, could result in various gases given off as it breaks down, at least for the first week or two. Did you water it good after you were finished? And continue to water as needed afterwards? If it's been really hot and dry there as you describe, anything that upsets the tree could cause it to react and show signs of stress.

The tree doesn't care a whit that a main leader would be cocked to the side, or if it is central and purely vertical. Neither does it care that there are secondary and tertiary leaders coming along as competition. It is only the human masters that care about this stuff. But it is telling you that it favors one particular trunk to be the main one by sending the preponderance of energy to it. I would listen to that message. If a straight-trunked, single leader tree is the end goal, then to achieve it, at some point not too far down the road, every branch but for one, the one that is to be the central leader, will be removed. The branches are young and flexible enough that any one of them could easily be "molded" into the straight and vertical central leader position. It would make sense to pick the strong one since it is obviously where the main growth is already directed. Just tie it to a 2x2 pointed stake driven firmly into the ground in order to make and keep it straight and vertical. After a year or two, the trunk will hold its shape and the stake can be discarded. My thought regarding whether to leave the other branches on or to remove them, is that neither option is really wrong. This dilemma is the one of focusing on form vs focusing on growth. More branches and leaves = more growth ... but we already know that in the end, it will all be removed from the finished form because it is growing in the wrong place. It will neither be a part of the adult tree trunk or of its canopy. Keep in mind that when X-amount of foliage is removed, 70 - 80% of X quickly regrows from the already established root system. Personally, I think it's worth the sacrifice of 20 - 30% short term size reduction to get the form established early in youth, such that all growth from that point onward is headed in a more correct direction (straight, single trunk.) Keep in mind that after the removed foliage is quickly grown back, that the tree will continue to grow ... because it's growing season. By the end of the season it will probably be 120%, or possibly more, of what it is now, with the problem of "who's the leader" having long been solved. Any knottiness of the young trunk caused by removing a cluster of branches at its base is a non-issue. This will automatically disappear in short order as the tree heals and gains size. That the tree has been in place for 4 years and is only this size (I understand that it froze back once) makes me wonder if you give it supplemental water and fertilizer, both of which are important in the early years. If you either don't, or are skimpy with these things, I'd give them a try and see if you can get some improved growth out of it, as by my standards, it's going too slowly for what it should be doing. After it's up and running, you could cut back.