Hello,

I’m sorry that your ginkgo tree is having problems. Ginkgo (Ginkgo biloba) is fairly easy to grow, enjoying well-draining soil in full sun. Read more here: https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=z990

Because it is tolerant of most conditions, the split in the trunk may have been caused by environmental conditions, such as improper planting which resulted in girdling roots or being planted too deep. Trees should be planted so that the root flare, the area where the trunk meets the root is as soil level Read more here: https://csfs.colostate.edu/wp-content/uploads/2022/05/How-to-Properly-Plant-a-Tree-Root-Flare_v2.pdf

The proper way to plant a tree is to set it in the hole so that the crown, or root flare is at soil level and the roots stretch out from the crown. It is also wise to keep the mulch, away from the trunk because the moisture that they hold in against the trunk can cause the trunk to rot.

It appears that the root flare of your tree is below ground level—the trunk seems to go straight into the ground.

However, planting may not be the only cause. Often, when a tree is raised in a container, the roots circle the container as it grows, so when you buy the tree, it may be girdled before you set it into the ground. In that case, the roots must be extended out from the trunk on planting. See how to plant a tree here: https://www.treesaregood.org/treeowner/plantingatree

If a root doesn’t want to be extended, it may have to be removed at the trunk.

A girdled root chokes off the movement of nutrients and water into the tree. They can also weaken or compress the trunk of the tree above the root collar flare which seems to be happening here. Read more here: https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/environmental/girdling.aspx

For proper treatment, I suggest that you contact a certified arborist. To find one in your area, go to: www.treesaregood.org the website of the International Society of Arboriculture, to find an arborist in your area.

I hope this helps you with your tree.

Thank you for contacting Ask Extension.