Deterioration of Ash

In the world of tree diseases, Ash Yellows is a significant concern for ash tree owners. This disease, caused by phytoplasma and spread by phloem-feeding insects, can lead to a decline in the tree's health over a period of 2 to 10 years, eventually resulting in its death.

The disease is characterised by a loss of vigor, sparse canopy, and the formation of cankers on branches and the trunk. These cankers cause twigs and branches to die back, and in some cases, witches-broom sprouts of growth might appear on some branches, particularly near the ground. Cracks in the trunk may also appear in this area.

It's important to note that there are no cures for declining ash trees. However, management to slow disease progression is possible. This includes removing trees with severe dieback, watering in periods of extended drought, fertilizing in the fall with a balanced tree fertilizer, removing dead limbs, and pulling mulch away from the trunk.

Ash trees are affected by more than one condition, including Ash Yellows Disease and Verticillium Wilt. To investigate and confirm if a tree is affected by a particular disease, resources such as the Iowa State University Plant & Insect Diagnostic Clinic, the United States Department of Agriculture (USDA) through its Plant Protection and Quarantine (PPQ) program or local Cooperative Extension Services, can be utilised.

For those living outside of Iowa, it's essential to contact the clinic first before submitting a sample. Instructions for submitting samples, including contact information for each state's diagnostic laboratory for U.S. residents, can be found on the clinic's website. The submission form should include the "DNA additional testing" box.

Prevention of ash decline includes proper tree planting and avoiding common landscape problems such as deep planting, girdling roots, mulch mounds around the trunk, soil compaction, root injury, and other factors.

Symptoms of ash decline include short internodes, tufting of foliage at branch ends, pale green to chlorotic (yellowed) leaves, and premature fall colors. Branches with living yellowing leaves are required for sample submission.

In some cases, ash trees may respond well to this management. However, it's crucial to remember that there are no cures for any of these maladies of ash.

In conclusion, while Ash Yellows Disease can be a significant threat to ash trees, proper management and prevention strategies can help slow its progression and maintain the health of these trees. Always consult with relevant authorities and follow best practices for tree care.