Something’s wrong with my Snowdrop tree’s trunk
Japanese snowbell or snowdrop trees, (styrax japonicus) are not know to have serious pest or disease issues. However, if stressed by growing conditions, beetles and scale insects sometimes become a problem.
Investigate the trunk and surrounding area closely. Examine leaves on nearby bushes for damage. One leaf in your closeup photo could be chewed by a rodent, which could also chew the tree bark. Cut the adjacent shrub away from the trunk, and pull back the mulch at the base. Is there a wound at the soil level? Could it be mechanical (shovel or string-trimmer for example) or rodent caused? Look carefully at the newest wounds for clues. The older wounds have callus growth along the edges.
Next, look for any holes in the trunk or branches. Note the shape, size, and if they are in a pattern or a random distribution. Holes might be caused by birds, or insect exit-holes, or boring insects feeding.
How did you plant and care for the tree? If stressed by sun and water conditions (too much, too little), having circling roots or being planted in a heavily amended planting hole are some reasons a new tree can fail to establish and thrive. Pests and disease become a sort of secondary issue, attracted by the stressed tree.
I’ll note that crowding the tree when young might not be an issue in your case, but as the tree grows it will compete with the conifers and shrubs around it in your site, likely shading them out, so consider that in your long-term landscape plan.
We are unable to make a site visit to examine your tree. Hiring a certified arborist is an option. We can troubleshoot issues here if you provide more photos and describe planting and growing conditions. Multnomah Master Gardener Volunteers are also available by phone or email.
Publications you may find useful about your tree, trunk wounds, ambrosia beetle, and contact information for volunteers.
Thank you so much for your reply. I think your suggestion that rodents may be the problem is quite likely. It’s so helpful to know the source of my problem!