The Curtis Park neighborhood has lost five elms to Dutch elm disease this season.
Dutch elm disease is a vascular wilt disease that causes the sudden wilting of leaves and can turn the entire canopy brown in just a few weeks. The disease is always fatal and there is no cure.
Elms are commonly infected in two ways: Elm bark beetles come from an infected elm and spread the fungal spores as they feed on healthy elms; or fungi are transmitted through roots that are grafted to an adjacent elm.
Hundreds of English and American elms have been removed in Sacramento since the summer of 1990, when Dutch elm disease was first confirmed in the city.
Control requires a lab test to confirm the disease, prompt removal and proper disposal of the wood.
A decade ago, SCNA acted to prevent the loss of all the English elms after Dutch elm disease caused the removal of several large English elms in Curtis Park. In 2007-08, SCNA appropriated money to treat 17 elms with the fungicide Arbortech 20-S®.
Dutch elm disease must be treated before the disease is present in the tree. The fungicide treatment is required every three years.
In late June, 11 English elms at the north end of Curtis Park were treated at a cost of about $880 per elm. One English elm in this group, due to declining health, wasn’t treated and will be scheduled for removal this fall.
Five elm trees in the two park areas adjacent to Donner Way were scheduled to be treated in August. However, those treatments were postponed due to concerns about the structural integrity of the elms. SCNA did not want to treat elms that might be removed.
Urban Forestry was contacted and will schedule an advanced inspection once all the leaves have fallen.
Since SCNA began treatment of the park elms none of them have become infected with Dutch elm disease. Some elms are exhibiting the classic Dutch elm disease symptom — branches with wilting/dead leaves – but this is caused by squirrels chewing on the branches.
More than 100 volunteers are monitoring the elms throughout the city for Dutch elm disease. When symptoms are spotted, the elm is turned into Urban Forestry, which submits samples to the California Department of Food and Agriculture for disease verification.
Since the cost to treat elms continues to rise, SCNA will be exploring ways to raise money to continue the treatments. Please contact me with your suggestions at [email protected].
By Dan Pskowski Viewpoint Staff