PORTLAND, Ore. — In the wilds of Portland, Ore., invasive species rule. Blackberries, thistle and ivy occupy pockets of brush, choking off native plants.

Enter the goat, scourge of the bramble. Urban goats are now getting a look-over, with early reviews being favorable.

“It’s like an old-fashioned solution to an old fashioned problem,” said David Kohnstamm, who works at an assisted-living facility that hired goats to clear a field. “It’s so obvious, but people don’t think of it.”

The goats are used in weedy patches between buildings and in lots gone to impenetrable thicket.

Many of the goats are provided by Georgina Stiner’s rental business. Here’s her sales pitch: Goats eat all day, but you pay by the acre, not by the hour. Goats don’t need time off or health insurance. They are chemical-free and will get the job done.

In five days on a 5-acre plot, Arthur, Patches, Copper and nine other goats have been hard at work clearing out the blackberry patch nourished by three particularly rainy years.

The goats were called in to do the heavy lifting on the restoration project that Stiner said has chased off less capable workers.

“Volunteers do their best, but in the end, it’s like they just scratched the surface,” Kohnstamm said. “They don’t make a dent, despite their best efforts.”

Stiner wouldn’t estimate the profits she’s generated off the business, Goat Rentals NW, but said most of what she makes goes toward feed, fencing and all the ancillary costs that come with one of Portland’s only livestock-mower businesses.

The largest lot the goats have cleared is 11 acres, with Stiner charging between $1,200 and $1,500 per acre.

“There’s a lot to eat in Oregon,” Stiner said.