Photo Courtesy ND Game and Fish Department

North Dakota Outdoors - Leafy Spurge

By Doug Leier, North Dakota Game and Fish Department

July 7, 2004 - Do you wander around your back yard or back 40 and wonder, "when will I ever get rid of all these weeds?"

I think about it often when I'm driving across the prairie and notice patches of leafy spurge, Canada thistle and purple loosestrife invading new territories.

Growing up in North Dakota, I never thought much about the ongoing fight against weeds. Their presence was just part of life on the prairie.

In the early 1990s, working in temporary positions for conservation organizations, I learned the importance of weed control for all landowners, not just natural resource management agencies. From owners of small city lots to rural landowners with thousands of acres, state law requires all of us to take action on noxious weeds on our property.

What sticks out in my mind, both then and now, is the work of all involved at solving the problem.

Leafy spurge is perhaps the most visible noxious weed in North Dakota. It grows on more than 1 million acres in the state, and over the last month, when spurge plants were in full bloom, it was easy to spot the yellow patches along roads and growing over countryside hills.

Leafy spurge is not native to North Dakota. Cattle get sick if they eat it, so when spurge grows on grazing land, it reduces productivity. In other areas spurge can grow in dense stands that crowds out mixed native vegetation. For wildlife, a mixture of plants is usually much better than one single kind dominating an area. That's why Game and Fish Department habitat managers are just as concerned about leafy spurge as are farmers and ranchers.

Traditional attempts to control spurge

Since leafy spurge came to North Dakota people have been trying to get rid of it. Chemicals have been the tool of choice for a long time.

Thousands upon thousands of gallons were sprayed in hopes of simply controlling the spread of leafy spurge, and perhaps that has been accomplished. But controlling the spread only means the number of acres still creeps upward every year.

Other methods have been tried. Goats and sheep were thought to be a natural alternative because they can eat spurge while cows can't. However, goats and sheep would only eat the spurge after other, more desirable food in an area was gone. Some people still use these animals but natural grazing hasn't caught on as a widespread solution.

Photo Courtesy ND Game and Fish Department

Biological control

In recent years, as the hype over goats was fading, spurge beetles were imported to North America. These beetles are natural adversaries of spurge in Europe and are gradually gaining a reputation for effectiveness in North Dakota.

Over time spurge beetles have passed test after test. As a function of nature these little bugs won't completely wipe out spurge, as they rely solely on the yellow plant. If that were to happen, the beetles themselves would die.

But they have slowed the spread of leafy spurge in some areas, and have actually reduced the number of spurge acres in other areas. And that comes at only a fraction of the cost to the landowner, compared with spraying chemicals.

The cost of fighting weeds

Scott Peterson, the Game and Fish Department's lands and development section leader, oversees nearly 200,000 acres the agency owns or leases for wildlife management. "We take noxious weeds very seriously," Peterson said. "Consider the ravines, coulees and hard-to-reach spots associated more with recreational property than traditional agricultural land, and you can understand the commitment we make to weed control. The spurge beetle is a great example of how biological agents can help."

The Game and Fish Department budget for weed control is more than $300,000 per biennium. During 2003, Peterson said, agency personnel sprayed just under 11,000 acres of noxious weeds. That includes salt cedar, Canadian thistle and leafy spurge.

Without beetles munching away at hundreds of acres of spurge, the cost would be much higher.

While skeptics continue to question the long-term viability of spurge beetles, the benefits are obvious in some areas.

"We've been fortunate enough with our successes," Peterson said, "to also distribute beetles to private landowners to aide the fight against leafy spurge. So far the results are impressive, with some areas showing remarkable results."

Leier is a biologist with the Game and Fish Dept. He can be reached by email: dleier@state.nd.us