Voles in the Vineyard

Girdled Grapevine

My nemesis.

Meadow voles.

They are basically field mice. and yes, they're fuzzy and plump and cute but I would really like them to go away now. So here's the problem: they chew around the base of the trunks of baby grapevines, thus girdling and killing the vine. Why do we have this problem? Lots of spring rains, organic farming, and terraces. It rained over 20 inches here between March, April and May. Therefore the grasses (wild oats, barley and native grasses), clover (which we plant on purpose as a cover crop), and weeds (bristly ox tongue, yellow star thistle, fluvellin, and many others) grew like crazy. We mowed four times! My grapevines are planted on terraces. Therefore we can only get to one side of the vine with a tractor (and mower, cultivator, etc.). We farm organically and because there are no effective organic herbicides we don't use any herbicides at all. Hence, LOTS of weeds. We weedeat all the terraces (by 'we' I mean my awesome crew and some temporary farm workers who work so hard) and under the vines. After weedeating, there is a lot of dried grass around the vines. This acts as a mulch preventing a lot of further weed growth but it is also protection for the voles from predators. We have many hawks, kestrels and owls living in the oak woodland surrounding our vineyard and they do eat the voles, but all the excess vegetation this year makes hunting difficult. We have put up some perches for the hawks throughout the vineyard and i definitely plan to put more up in the next few weeks. This past week, the vineyard crew spent a couple days shoveling out weeds in a 3 foot swath under the vines. The hope is that this will give them less protection from predators. I have had 150 mouse traps on the ranch for the last two months (we bait them with peanut butter). They work, but catching 20-30 voles a day doesn't make much of a dent when there are thousands and thousands. I need to find birth control for voles. Or an organic, less toxic bait would be good. I did finally have to put out vole bait in one area - it works. The bait I use is not toxic to secondary consumers so birds that eat the dead voles should be fine, but I hate putting poison out in my vineyard. But I also cannot let my vineyard be killed by these buggers!

Baby Vines in their "Second Leaf"