Staffers at Davenport's Nahant Marsh have tried all kinds of ways to get rid of invasive plants that crowd out desirable native varieties. They've mowed, pulled, cut and treated stumps with chemicals.

But despite years of repeated efforts, the problem continues.

So when Nahant facilitator Brian Ritter heard of other natural preserves using goats to tackle the problem, he decided to give it a try.

Twenty-four goats from Wisconsin were delivered in late May, and the change has been phenomenal.

"We put them in an area in early morning, and when we came back in the afternoon to check on them, I just couldn't believe how much they had cleared," said Amy Loving, a naturalist at the center.

 "In the morning, you couldn't see through the understory, it was so filled with brush. But in the afternoon, you could see daylight.

"They've done a lot more work than we were expecting. It's unbelievable the amount of work they are doing and how cost-effective it is. They've been wonderful."

The goats are kept inside a portable fence that is moved every day and a half to two days to make sure they have plenty of fresh food.

In addition to garlic mustard, other invasives are poison ivy, reed canary grass, wild grape and soft woods, such as boxelder and mulberry trees.

The goats are being rented for $2 a day through Friday and are part of a three-year pilot project funded by grants. Benefactors include Cargill Inc., the Riverboat Development Authority and an area family with an interest in the marsh, Loving said.

One question the staff hopes to answer is whether, after three years, some of the invasives actually stop coming back. That is, not only to have the goats chew them down in a given season, but also to kill them off entirely.

If that is the case, maybe Nahant will try to get its own goats, Loving said.

Nahant is a wetland area in west Davenport owned by the city and administered through a consortium of groups.