A large number of repellents are labeled to limit vole damage. Products formulated with thiram, capsaicin, garlic oil, garlic powder, putrescent whole egg solids, sodium lauryl sulfate, mint oil, oil of rosemary, castor oil, sorbic acid, and "hot sauce" are all registered for controlling vole damage on ornamental plants. None are registered for use on gardens or plant parts destined for human consumption. Be doubly careful to read the label and follow its instructions carefully.
Repellents are relatively expensive and provide only short-term protection. Precipitation may wash some off. When foods are in short supply, such as in winter, the effectiveness of repellents usually decreases. Do not use electronic repellent devices, moth balls, or other unregistered products because no evidence has been produced regarding their effectiveness on voles.
Additional information on vole management can be found at:
Voles
Vole publication
