The D.C. Department of Transportation will begin injecting hundreds of the District’s estimated 8,000 American elm trees with chemicals this week to protect them from Dutch elm disease, officials said.
The trees, which are found in all eight wards of the city, were chosen as part of the original design of the city due to their trademark canopies and because their root systems tend not to tear apart sidewalks, said John Thomas, DDOT’s supervisory forester.
The disease, which peaked in the 1950s and 1960s and destroyed thousands of trees, is still prevalent in the city and forces as many as 400 trees to be removed and replaced annually. Dutch elm is introduced into trees by the Dutch elm bark beetle, which burrows into the trees’ ridged gray bark.
Thomas said workers will begin pumping as much as 80 gallons of chemicals into between 100 and 250 trees beginning today using a mechanical syringe.
The city nearly tripled its funding for the chemical program from $35,000 to $97,000 this year, Thomas said.
Thomas said like humans, the disease tends to attack trees “stressed” by drought or disruptions to root systems, but said there is little residents can do to avoid infection. A single elm tree can digest up to 250 gallons of water a day.
History of the elm
» Pierre L’Enfant chose the elm tree as part of the original design of the city.
» Elms are perfect for city streets because old or dead branches tend to peel like bananas and fall slowly rather than crack and fall quickly to the ground, officials said.
» Telltale signs of Dutch elm disease are very similar to signs of drought including drooping and dry leaves and branches.
» Residents can call 202-727-1000 to report trees they think may have the disease.
