Cracks in bark-Purple Robe Locust What 2 do
I planted 10 gallon Purple Robe Locust approx 3 years ago (was probably 12' tall at the time); and now it's grown to about 16' high and looks very healthy. However, I noticed yesterday while watering it - that it has about a 9" Vertical crack all the way through the bark to the wood of the tree. This crack starts about 10" up from the ground & has separated the bark completely from the tree approx 1 1/2" on either side of the bark split--leaving a gaping hole to the wood. I've never seen this? I will say the tree has certainly grown the most this Spring/and looks healthier than it ever has... but I'm worried that if I don't treat the crack it may well kill the tree? Any Suggestions?
Sunburn Cracks Trunk Bark
The location of the crack and the way it is described sounds like sunburn. If this is so it will not be on the north side, more likely on the west but not always. Trees with small canopies in youth, like yours, do not have the ability to shade their own trunk. The result is that sun beats down on the tender young bark and causes sunburn. Tree bark peels from sunburn just as you do, and in this case it has cracked and separated. Often bark boring insects enter the tree through such openings and their larvae can invisibly ring it to cut off the link from root to leaf. Farmers paint the trunks of their orchard trees white to protect them from sunburn. You can wrap it loosely in burlap to prevent further burn - looks better than white paint in the ornamental landscape.
Some great advice from Mo Plants. There are other reasons that bark will split on trees. Take a look here to see what might fit your situation.