Landscaping by sheep - or goat - may be fodder for the "Colbert Report"…

Audio from Colbert Report: "Goats, if you're going to steal our landscaping jobs humans are going to start producing feta cheese."

But it's a real money-maker for California sheep producers.

"We've seen an increase in urban areas that typically would require either some sort of spray or human labor hours."

Lesa Carlton heads the California Wool Growers Association. She says more California sheep and goat producers are renting their flocks out as eco-friendly alternatives to herbicides and gas-powered mowers.

One of those producers is Ed Anchordoguy who has 120 sheep in Sonoma County. His animals were used to graze in environmentally sensitive wetland areas…places where tractors and other equipment would have been detrimental.

"The sheep were doing something that it would be hard to duplicate mechanically - vernal pools, obviously there's wet areas, and the equipment would have caused more damage."

Rising fertilizer prices have also made grazing services a cost-effective alternative for farmers.

But critics say sheep grazing may actually worsen the spread of invasive weeds. Some plant ecologists say the sheep may be picking up the seeds in their wool and dropping them in new areas.