Got water weeds?

To report possible yellow floating heart or water primrose infestations, contact Ed Keith, Deschutes County forester, by phone at 541-322-7117 or by email at edk@deschutes.org, or Mike Crumrine, Oregon Department of Agriculture noxious weed specialist, by phone at 541-604-6580 or email at mcrumrine@oda.state.or.us.

Photos courtesy Oregon Department of Agriculture

A pair of aquatic invasive plants have reached Deschutes County ponds, and weed managers are asking the public’s help in determining the extent of the infestation.

The first reports of the weeds on the east side of the Cascades came a couple of weeks ago, said Mike Crumrine, noxious weed specialist for the Oregon Department of Agriculture. Yellow floating heart is covering two stock ponds, where water is held for livestock, near Redmond, and water primrose blankets a third of an irrigation pond near Terrebonne.

“As rapidly as these two infestations have grown in their localized areas, it wouldn’t surprise me to find more,” said Crumrine, who works out of Prineville and covers Oregon counties along the Cascades’ east slope. The landowners at one stock pond near Redmond and an irrigation pond near Terrebonne first noticed the plants growing last year and then saw them erupt this summer.

While responding to the report of overwhelming weeds at the first stock pond, Crumrine discovered yellow floating heart in a second stock pond about 100 yards away on a neighboring property.

Both weeds have yellow flowers and thrive in still water such as ponds. Crumrine asked that anyone who finds the weeds to call him or the county.

“We are going to need have as many eyes out as we can for these new invaders,” he said.

How the weeds got here is a mystery. They may have arrived by waterfowl.

“These are aquatic weeds and both of them, yellow floating heart and water primrose, are abundant in California, along the same flyways that we share for migrating ducks and geese,” Crumrine said.

They have burr-like seeds that may have clung to birds. Someone may have also unintentionally brought the weeds from waters west of the Cascades, where they’re already found.

Douglas, Lane and Linn counties have all had problems with the plants, said Deschutes County Forester Ed Keith.

Like Crumrine, Keith said anyone finding the weeds should call or email, but he hopes the infestations near Redmond and Terrebonne are isolated.

“To tell you the truth, I’m hoping we don’t get any calls,” he said.

If yellow floating heart or water primrose spreads into a pond, lake or river, the weeds may cause havoc for plants and animals there. The weeds crowd out native plants and sully fish habitat. They drop the amount of food available for waterfowl while increasing the size of breeding grounds for mosquitoes. They also affect fishing and swimming.

“Both of these plants could form a mat dense enough that it will choke up boat motors, make it impossible to row through,” Crumrine said. “It is a jungle of underwater vines.”

The plants are originally from Eurasia and were brought to America more than a century ago “as pretty plants,” Crumrine said. They were mainly a problem on the East Coast but now they are being found in western states.

The weeds aren’t the first from Eurasia to be a problem here. Eurasian watermilfoil has been spreading around the Northwest since the 1970s and is likely the result of people dumping fish tanks. The plant was used as decoration in the tanks.

Surveys have found the weed in four bodies of water around Central Oregon — East and Suttle lakes as well as Crane Prairie and Haystack reservoirs.

While Eurasian watermilfoil may pose some of the same problems as yellow floating heart and water primrose, Crumrine said he considers the latest invaders as bigger threats.

“They seem to spread more quickly than the milfoil,” he said.

The Oregon Department of Agriculture is offering to treat waters infested with the weeds for free, Crumrine said. Treatment involves waterborne herbicides, which he said aren’t released in levels high enough to be harmful to animals for people.

In the Willamette Valley, the agency has found that treatment will knock down the amount of yellow floating heart but not completely rid waters of it.

Waters treated for water primrose have gone two years without a re-emergence of the weed, but it is unclear whether it will come back.

“Eradication is a tough status to obtain,” he said.