Thank you for your question and for including the photos.

Because your neighboring Honeycrisp trees appear healthy, the problem is likely specific to this tree rather than a disease affecting all of your apple trees. Possible causes include winter injury, root or trunk damage, planting too deeply, or another source of stress that affected only this tree. Although the green tissue beneath the bark on a small branch is encouraging, the poor leaf development this spring, lack of fruit, and widespread browning suggest the tree has experienced significant stress or damage.

One thing that stands out in the photos is the rock mulch touching the trunk. Rock mulch absorbs and radiates heat, which can increase stress on young trees, and any type of mulch should be kept several inches away from the trunk. It's also important that the root flare (the point where the trunk widens into the roots) remains visible above the soil line. Trees planted too deeply or with mulch piled against the trunk are much more susceptible to decline.

At this point, the most important step is determining whether the main trunk is still alive. Try the scratch test in several places on the trunk. If you find green tissue beneath the bark on the trunk, the tree may still recover, although it could take time. If the trunk is brown and dry beneath the bark all the way down, the tree is unlikely to survive.

If the trunk is still alive, I would recommend:

- Pull the rock mulch back so it does not touch the trunk and expose the root flare.

- Water deeply during dry periods (about 1 inch of water per week).

- Avoid fertilizing this year, as it can place additional stress on a weakened tree.

- Wait until next spring before doing any major pruning so you can see what, if any, new growth returns.

These University of Minnesota Extension resources provide more information:

Apple tree care and maintenance: https://extension.umn.edu/fruit/growing-apples

Planting trees and shrubs: https://extension.umn.edu/news/planting-trees-and-shrubs

Planting for the future: Why technique matters for trees: https://extension.umn.edu/news/planting-future-why-technique-matters-trees

I hope this helps!

-Victoria

University of Minnesota Extension Master Gardener Volunteer