Dutch elm disease cases at an all-time high in Saskatoon

Dutch elm disease (DED), which has led toa record number of trees being culled in Regina this year, isalso spreading in Saskatoon.

The City of Saskatoon's parks department has confirmed six new positive cases of DED:three in the Varsity View neighbourhood, one in North Park and two in Westmount. The city has activated its DED response plan.

"It's the highest number of positive cases we had in a year. In previous years, we had typically one or two. In the last couple of years, we have seen an increase,"Thai Hoang, director of parks, said Thursday morning.

"What that means is the immediate removal of the six infected trees, as well as any nearby trees that may be exhibiting symptoms of Dutch elm."

Hoang said the department has conducted 91 tests and received results from 54 trees so far. A total of eight trees will be removed as the department awaits the remaining results. He said staff is also sweeping the vicinity of infected trees to remove as much stored elm wood as possible and has already taken more than 2,000 kilograms.

He said that while the disease has been in the city since the 1980s, it hasn't appeared frequently. He said there were four positive caseslast year.

DED is caused by a fungus carried by the elm bark beetle. Once the fungus takes hold it affects the vascular system of the tree, preventing it from getting water and eventually causing it to wilt and die.

Hoang said residents should check any elm trees on their property for signs of the disease, such asleaves wilting and turning yellow, then curling and turning brown.

Anyone who suspects an unhealthy elm tree or is unsure of what type of firewood they have can take a photo and complete anonline form or contact urban forestry.

Hoang said it's important to curtail DED because about a quarter of the urban forest is elm. He stressed that residents should not store or transport elm wood or brush.

"Doing so, or keeping elm wood to burn in your fire pits or for other purposes, it really puts our urban canopy at risk."

He asked residents to take any elm wood to the landfill for disposal, rather than putting it in green bins.

"The only safe way of disposing of Elms is at our designated site at the landfill."

Regina has culled 36 trees infected with Dutch elm disease this year, the most for a single year in that city.

LISTEN |City of Saskatoon entomologist Sydney Worthy appeared on Saskatoon Morning last year to discusshow important it is to prevent Dutch elm from spreading:

Saskatoon Morning7:22Positive cases of Dutch elm disease are threatening the city's majestic elm trees

The City of Saskatoon Parks Department has confirmed another positive case of Dutch elm disease in Forest Grove. It's the fourth occurrence this year after several cases of the disease were identified in Sutherland and Pleasant Hill. Candice Lipski talks with City of Saskatoon entomologist Sydney Worthy to find out just how important it is to prevent Dutch elm from spreading.