Question: I’m interested in doing regeneration planting of oaks and hickories on my property, and have made attempts with both direct seeding, as well as starting in Rootmaker containers and then planting the seedlings after one year of growth. I have been having a major problem with voles, despite my best attempts at barriers, and am wondering if there is anyone who would be able to advise me?
As an example, I had a black oak seedling, one year old, with great growth, about 18″ tall and with a rootball of comparable size, which I planted this fall. After 2-3 months, in December, the entire root system was eaten and all that remained of the seedling was the stalk, with clear gnaw-marks where it had been chewed off at the base. It was protected by a wire mesh enclosure that covered all sides plus the top, and was set about four inches into the ground. The mesh was finer than the standard chicken wire; the openings were about dime-size.
I would appreciate any guidance your experts can share.
Answer: Based on your description, it certainly sounds like pine (=woodland) voles, Microtus pinetorum, although trapping would be needed to confirm. I am no longer doing work on voles, but earlier work, Selective Feeding of Pine Voles on Roots of Seedlings, showed that they really do like roots of oak seedlings.
When I want to exclude small mammals, I use ¼ inch mesh size or smaller. One other approach I’ve used with success is to create an “apron” of hardware cloth underground and extending outward several inches from the cylinder. Since pine voles create tunnels below the ground surface, this isn’t a guarantee of exclusion, but it certainly should discourage them.
If the problem is too severe for you to tolerate, a rodenticide bait such as zinc phosphide is another option. Thiram is a repellent that could be used – like all repellents, it has variable and short-term effectiveness (but still tends to be better than other commercial products).
The following link offers some practical tips on voles and vole control, including trapping to verify that voles are present, and methods of scouting and treating with rodenticide to reduce exposure risk to other nontarget wildlife and pets, Controlling Voles in Horticulture Plantings and Orchards in Missouri, University of Missouri Extension.
Voles!, Purdue Extension-Agronomy
Volves (remember the V), Turfgrass Science, Purdue Horticulture & Landscape Architecture
Dealing with Mole Damage in Your Yard video, Purdue Extension-Forestry & Natural Resources YouTube Channel
Orphaned Wildlife, Got Nature? blog
A Template for Your Wildlife Habitat Management Plan, The Education Store, Purdue Extension resource center
Forest Improvement Handbook, The Education Store
Wildlife Habitat Hint, Purdue Extension – Forestry & Natural Resources (FNR) YouTube Playlist
Conservation Tree Planting: Steps to Success, Purdue Extension – FNR YouTube Video
Woodland Stewardship for Landowners, Purdue Extension – FNR YouTube Playlist
Woodland Management Moment, Purdue Extension – FNR YouTube Playlist
Rob Swihart, Professor of Wildlife Ecology
Department of Forestry and Natural Resources, Purdue University