The European Bird Cherry tree is popular for its white flowers and fragrant smell when the spring bloom hits, but it's an invasive species crowding out native trees in Anchorage.

The Anchorage Assembly passed an ordinance this week banning the sale of the trees, commonly known as May Day trees. The ordinance introduced by Assembly member Forrest Dunbar also bans the sale of Reed Canary grass.

Dunbar said the feedback he's received has been positive.

"It did educate people that these are dangerous for our habitat and I think the next step is some private citizens will remove their trees, but again, that's their own decision," Dunbar said. "That's not something we're going to force upon them."

Tim Stallard, invasive plants program coordinator with the Anchorage Parks Foundation, said May Day trees are toxic to moose and have a habit of crowding out native trees. As a result, it harms the food source for salmon, because the insects they eat feed on native trees. He said the ordinance is helpful in trying to contain the problem in Anchorage.

"That's a great step towards preventing the additional spread of this problem species through sale," he said. "But there are already a lot of them out there-- both in people's yards, as well as growing wild in our natural forested areas."

Stallard said they go out with volunteers to pull small seedlings in Anchorage parks, but many larger trees still need to be cut down. It's also a multi-step process in making sure the tree is effectively killed.

"You can't just cut them," he said. "The trees will resprout and spread very vigorously. We need to treat the stump with an herbicide. If we were to just leave it in the forest, that tree, its branches, any firewood logs, those could sprout roots and regrow."

Another way to ensure the trees that are cut down won't spread again is to lay it out on landscaping fabric, Stallard said.

"They'll dry out and die and we can let it scatter the debris," he said.

Stallard said the work he does is funded by different environmental-related grants.

"Support current work and future projects," he said. "People do have concerns with herbicides that are understandable, but if we balance the short term lower risk of herbicides versus the long term major impacts these species can cause, the balance is in favor of getting rid of these."

Dunbar said it's unlikely the city can form a dedicated program to cut down the trees right now, due to budget issues. Anchorage Parks and Recreation Director John Rodda also cited budgetary concerns as a reason why there can't be staff or equipment set aside for tree removal but said the department would look at outside grants.

"I don't think in the near future we're likely to set up that kind of fund, but it's something we can aspire to down the road," Dunbar said.

Stallard said it's also important to continue raising awareness about the invasive plant.

"Alert the other communities across the state," he said. "Kenai Peninsula, Mat-Su Valley -- get them to address it sooner."

Rodda said he's received calls from private homeowners asking the municipality for tree removal help, but the city can't work on private property.