RALEIGH, NC – Hair clippings, cayenne pepper and raw eggs – these are just a few of the odd ingredients  recommended to keep those pesky deer away from your backyard garden. But what about farmers who have hundreds of acres of Christmas trees to protect? North Carolina State University extension specialists have now found an effective, inexpensive alternative to available commercial products to keep the deer at bay.

The NC State researchers, led by Jeff Owen, a Christmas-tree production specialist, are exploring the use of  inexpensive, inedible food byproducts – such as dried blood and egg powder – typically sold in bulk to the pet-food industry to be used for flavoring.

Less expensive repellents

These byproducts cost 85 to 90 percent less than their commercial counterparts, and are found to be just as effective. Using these repellents – which can be purchased locally in bulk – may provide tree farmers an early Christmas present.

“These products have an unappealing taste, but the decaying smell actually elicits a fear response in the deer and keeps them away from the crops,” Owen says. “We’re continuing to look at similar products – like liver powder and fishmeal – to see if they work the same way.”

Owen says that Christmas-tree farms in North Carolina have long dealt with deer who harm the trees by horning (thrashing market-sized trees with their antlers to mark territory) and browsing (eating the buds and shoots off  young trees.)

Damage can be extensive

Not all Fraser fir growers contend with these problems, but where deer populations are high, deer can eat young trees down to a pencil-sized stem. Damage can be so extensive that growers have abandoned fields of  young trees. Hard-pressed growers will use a combination of selective hunting, deer repellents and food plots to divert deer from their trees.

“We initially looked into the effectiveness and feasibility of using different fencing and commercial repellents to protect trees and crops from deer. Both are successful, but are extremely expensive,” Owen explains. “When you take the commercial deer repellent that you find at your local hardware store and use it on a farmwide basis, you see growers  budgeting as much for deer repellents as most of their other pesticides.”

Commercial deer repellents are so costly that Christmas tree growers use them at half-strength to be able to afford using them at all.

NC State and the N.C. Christmas Tree Association provided support for the research.