SIOUX FALLS, S.D. (KELO) – In city officials’ eyes, the fight against the Emerald ash borer has reached halftime. 

First discovered in Sioux Falls in 2018, the Emerald ash borer (EAB) has spread across the city, and city officials expect the spread density to increase dramatically in the next 5-10 years. Five years into a plan to remove all ash trees from public right-of-ways, city crews have removed more than 13,700 ash trees and plan to have more than 15,800 ash trees removed by the end of 2024. 

“We have about 23,000 public ash trees to be removed. You subtract the 5,500 trees that are being treated by a homeowner and our target becomes about 17,800,” Brett Kollars, assistant director of parks and rec told city council members Tuesday. “At halftime, we are ahead of schedule when it comes to our EAB response plan in public spaces.” 

Kollars said once city crews finish removing all the ash trees, crews plan to reach out to private homeowners about removing trees from private property. 

“The onus of this is really shifting to the homeowners,” Kollars said. “Know what you have on your private property. Do you have an ash tree? Next is a decision point: treat or take down. The third step of that too would be replanting.” 

Treating ash trees needs to happen every 2 years depending on the product being used. Treatment costs range from $150 to $350 per treatment depending on the size of the tree. 

Council member Greg Neitzert asked if it is too late for homeowners to start treating ash trees. 

Urban forestry specialist Bryan Peterson said it’s not too late as long as the tree hasn’t lost 30-40% of its branches. 

Peterson said EAB attacks the tree from the top-down starting with shrunken leaves at the top or the tree and then branches dying.

“It’ll look like the tree is bald,” Peterson said. “The problem comes 2-3 years after the tree dies because the wood becomes very brittle.” 

Peterson said treating ash trees is like putting on bug spray to defend against mosquitoes. 

“If you don’t reapply, you’re going to get bit,” Peterson said. 

Neitzert also asked about tracking ash trees with private homes. Peterson said the city surveys neighborhoods once a year from the street and identifies ash trees. 

“The more education we can put in the homeowners’ hand, the better it’ll be,” Peterson said. 

Kollars said there’s a decent amount of ash trees in natural areas, like near the Big Sioux River and bike trails. Peterson added any ash trees that could cause damage or a future issue to the bike trail have been removed but there’s still a lot of ash trees in natural areas. 

Kollars said the city earned a $3 million grant over five years to help disadvantaged community neighborhoods, as identified by the U.S. Census Bureau, with the removal of ash trees. 

Ash tree movement prohibition repeal 

Since the start of the EAB infestation, homeowners and city crews have been banned from moving ash trees from Labor Day to Memorial Day. That was to help slow the spread of the infestation, but now the spread has impacted all areas of the city and the prohibition time period will be repealed. 

City officials will recommend the ash tree movement repeal on Nov. 7 and Nov. 14 city council meetings. 

“The moratorium did its part and slowed the movement of EAB containing it to some degree bringing us to this point,” Kollars said. “Now with documentation of it everywhere, we can repeal that and allow the arborist more time to do their job.” 

Get $50 tree for planting a street tree

The city has a goal of replacing 750 street trees each year and there’s been 450 trees replanted on the street in 2023. 

For each street tree planted, the city pays a $50 voucher after regulations are met, a city-approved permit is issued and a proper tree is purchased by a participating nursery. 

There’s more than 20 different kinds of trees homeowners can get a $50 voucher for planting.

“The goal within the entire city is to plan to have no more than 20% of any one given tree family,” Kollars said.