Seldom Seen Plant Destroying Multitudes

April is the time to savor freshly caught trout. My kitchen is in the back of my house. The window looks out on 95 percent of my property, most of which is a small back yard, gardens, shrub and herb borders, and a rather moist, open field giving way to woods down to the brook. This window looks out on my bird feeders, too. I love to cook and spend a lot of time in my kitchen.

A common sight in April is seeing my two cats keeping vigil out in the field. They sit in one spot for quite some time and then pounce. The field is pockmarked with little mounds of soil. Lots of them. My cats return to my deck at the kitchen's back door with the headless remains of voles. This is on a regular basis, and it's just fine with me.

These are the earth-movers that can wreak havoc with your plants. There are a couple of others whose handiwork is much in evidence, too: moles, skunks and woodchucks, but we'll save them for another time. They are not nearly as destructive to plant life.

There are two kinds of voles, and we here in the Catskills have them both. If plants and bulbs and hostas, in particular, have been disintegrating in your well mulched beds and borders, the likely culprits are pine voles, aka woodland voles, Microtus pinetorum. They are small rodents, no longer than five inches including their very short tail; they have smooth, velvety chestnut-brown fur and tiny, almost unnoticeable eyes.

Look for small, slightly cone shaped mounds, with holes about the size of a quarter. Preferring soft loamy soils like our improved beds and borders, pine voles live below ground in long connected tunnels. As we walk over an area inhabited by pine voles, the ground feels soft and spongy beneath our feet. The underground portions of plants are their favorite food, bulbs being the choicest. They will eat tubers (potatoes, peanuts, etc.) and most roots, as well as seeds and bark. No plants are safe if they inhabit soils that are easily burrowed through -- flowering plants, vegetables, fruits, ornamental trees and shrubs, even roses are all fair game.

So, we go to great lengths providing the optimum soil for our chosen flora, and, as the expression goes, "... if you build it, they will come". Pine voles are especially attracted to beds and gardens that have mulch applied over bare ground. Soft fine mulch like shredded bark or pine needles provides them protection from predators while they forage for food. They can tunnel through leaf litter and similar mulches near the surface, but they also can, and often do, burrow to depths of twelve inches. There go the bulbs!

If your gardens and beds are mulched, and you are losing plants to what may be vole activity, remove the mulch away from plant stems and trunks; better yet, remove it altogether. If you succeed in banishing the pests, you can reapply it.

Trapping is the most effective way of combatting these destructive creatures. Pine voles are most active in winter when food is in short supply. With snow cover, there is little you can do. With the first opportunity in early spring to remove mulch, also purchase some snap back mouse traps.

Depending on your allegiances, this could become all out war, or just a mild incursion. My dear friend, Carl S., enlightened me many years ago. He told me, in essence, that "... to the degree that you're unhappy about something, to that same degree you'll do something to change it". It seems not many degrees more of less. We used to call it a "truism".

First step, place small apple pieces in entrance holes in the evening. Next evening, set the traps baited with apple slices right next to the hole. Cover both with an overturned pot or bucket to prevent non-target animals from investigating. Assuming you are successful, continue several days after the last in caught to ensure complete eradication.

Yes, I did state that there are two voles that take up residence when the habitat is suitable. The other is the meadow vole, aka field mouse, Microtus pennsylvanicus. Slightly longer than the pine vole, about seven inches total, including their 1-1/2" to 2-1/2" tail, this fellow is one of the occupants of my moist field.

Field or meadow mice like a habitat that has overgrown taller grasses. They construct shallow surfaced runways by closely cropping the grass for their little highway through the taller protection from predators. Most of the damage they inflict on plants is above ground. Not only can they destroy forage crops, but they also cause considerable damage to herbaceous and woody plants by girdling the latter and killing them. The meadow vole is the scourge of young fruit tree orchards.

The very best way to combat this pest is to maintain closely cut fields and meadows where they are an important food source for birds of prey and other carnivores. If there is danger to young fruit trees where the risk of damaging the bark from mowing equipment or string trimmers is high, placing snap back mouse traps in the clearly evident runways and baiting them with peanut butter and oatmeal can be very effective.

Constant vigilance is really important, as the population of meadow mice can explode to several hundred per acre. Each female can produce nine litters of eight each, every year. Fortunately, they have an abundance of predators that include hawks, owls, herons, crows, skunks, snakes, cats, opossums, even shrews. Their average life span is fourteen to eighteen months.

These seldom seen visitors feed mostly at night. April is the time to send them their eviction notices, once and for all. I would only recommend toxic baits to commercial growers that were suffering the threat of economic losses. For the homeowner, my suggestion would be to try thiram, a taste aversant, placed right into the hole. Experiment.

I've read about, but can't vouch for, a variety of solutions: peppermint oil, castor oil, well used kitty litter, oil soaps, cayenne pepper. I guess if you're going to try to save your hostas, daylillies, tulips, roses and other garden favorites, interspersing with plants that have poisonous roots might be a big deterrent.

Finally, adopting or borrowing a couple of really good mousers, and not overfeeding them, is most effective at telling the little rodents to get out and stay out, or else ... it's curtains!


From The Garden of Ed. Submitted for publication in The Towne Crier on April 7, 2004

© 2004 Ed Mues. All Rights Reserved.