Autumn Blaze Bare Root Trunk Question

Question: Hello. In April 2023 we purchased 2 bare root autumn blaze trees from our reputable nursery in Mankato. By spring of this year, 2024, we noticed the bark on the trunk towards the ground looked like the attached pictures.  We worked with our nursery and they offered to replace the tree. We replanted.  Now later this summer, the other one we purchased in 2023 started showing the exact same thing. Attached pictures are from this one. We are beyond our one-year warranty on the tree so we will have to pay to replace, if that's necessary. Any idea what this is and if it is treatable? Our tree company recommended I send this email and said he has always had good success.  I'm keeping my fingers crossed. The new one we replaced in spring looks just fine.

responder: Linda G Tenneson, Benton County Extension Master Gardener & Tree Care Advisor Replied September 08, 2024, 2:56 PM EDT
response: It could be animal damage.  How do you mow the grass? Do you use a string trimmer to cut the grass close to the trunk? The circulation system for trees is immediately under the bark. If this is cut on one side of the the tree, that side will die. If it is cut all the way around, the entire tree will die because there is no way for water and nutrients to travel from the roots to the leaves. If the tree appears to be healthy on top, put a ring of mulch around the trunk, but NOT touching the trunk. Also a barricade of chicken wire or hardware cloth to keep a gnawing animal away from the trunk if that is causing the damage.  Another possibility is that the tree was planted too deeply. I do not see any sign of a root flare at the base. See these web pages. https://extension.umn.edu/how/planting-and-transplanting-trees-and-shrubs https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/insects-pests-and-problems/environmental/mechanical https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5353715.pdf https://tfsweb.tamu.edu/uploadedFiles/TFS_Main/Urban_and_Community_Forestry/About_Urban_and_Community_Forestry/Urban_Forest_Information_Sheets/Tree%20Health%20-%20Injury_Squirrel%20and%20Other%20Small%20Animals.pdf

responder: The Question Asker Replied September 08, 2024, 3:52 PM EDT
response: Thanks.  I have a feeling my husband nicked it with the weed whip early on and it has just progressively gotten worse. He hasn't used the weed whip for months around it, but I bet he nicked it just a bit and now it is progressing. So based on this, the tree will die.  Any suggestions for best time to replant something? On Sun, Sep 8, 2024 at 1:56 PM Ask Extension <<personal data hidden>> wrote:

responder: Linda G Tenneson, Benton County Extension Master Gardener & Tree Care Advisor Replied September 08, 2024, 5:30 PM EDT
response: See this web page. Planting time depends on whether the tree is bare root, balled and burlaped or field grown and dug up. But please follow the directions on the planting depth. Don't plant covering up the root flare and make a grass free circle around the trunk covered with mulch. But don't let the mulch touch the trunk. Keep it a few inches away.  https://extension.umn.edu/how/planting-and-transplanting-trees-and-shrubs