Official Newspaper of Eddy County since 1883

Tree Talk: July 12, 2021

American elm is North Dakota's state tree. It is these canopies that, with their beautiful vase-shape, form leafy "tunnels" along elm-lined streets. Elms were a natural choice for planting in communities and windbreaks because it was one of our tough native species. Then, the unthinkable happened: Dutch elm disease (DED) entered the U.S. in the 1920's and found its way to Mandan in 1969. It has spread to every county of the state, decimating American elms in North Dakota's communities, windbreaks, and native forested stands. Dutch elm disease is caused by a fungus which infects the vascular system, stopping the flow of water from the roots. The disease is transmitted by small bark beetles from infected trees to healthy trees, or it can pass from a diseased tree to a neighboring elm tree through root grafts. The first signs of DED are "flagging" branches, where leaves wilt, turn yellow and then brown, and finally fall to the ground due to lack of water. Prompt removal and disposal of infected trees (including infected firewood!) is key to managing DED in any community. The cities of Fargo, Grand Forks and Bismarck still offer the "elm tunnels" along streets in old neighborhoods, possible because of the aggressive management of DED in these communities.

So – is this the end of American elms in small towns? No! There are DED-resistant elms widely available in the nursery trade. Diversity is key to a sustainable "community forest", and elms are being replanted in many communities. 'Prairie Expedition' is an NDSU release, propagated from a 'lone survivor' native elm discovered along the Wild Rice River in the southeastern corner of the state. This selection shows great resistance to DED and is a wonderful option for increasing the elm populations in North Dakota communities. Other elms that work well in North Dakota include 'Princeton' and 'Valley Forge'. Hybrid elms include 'Cathedral', New Horizon', and 'Pioneer.' apanese elms to try include 'Discovery' and one from NDSU that produces a beautiful fall burgundy-red canopy, 'Northern Empress.'

Take a Look: See 'Prairie Expedition' American elm trees recently planted on the 1100 block of 3rd Ave North. The photo above shows one of the most majestic mature elms in New Rockford, which is located on the corner of 2nd Street South and 2nd Avenue South, where it graces the entire front yard of this home.

REMINDER: WATER your trees weekly, both young and old, with a slow trickle from a hose. Mulch any newly planted trees to retain soil moisture, suppress weed growth, and to keep mowers and trimmers away from tender bark on young trunks.