Vole trouble

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on March 03, 2011 at 9:41 AM, updated March 03, 2011 at 9:58 AM

volebloc.JPGVoleBloc, a jaggy product that discourages vole tunneling.

   Q: I've had trouble with voles eating roots from underneath my hosta. I've tried caging them, but the voles tunnel right underneath. I read it's possible to keep them away from plants by adding gravel or some kind of sharp material to the soil.

   Do you know what size/type stone to use? And how much do you need to put down?  Just a little or am I going to want to apply it like mulch?

   A: Some people have had success with that approach. The premise is that voles don't like tunneling through jaggy soil. The key is working enough jaggy stuff into the soil (i.e. crushed shells, chicken grit, gravel, slate fragments, etc.) to discourage voles from wanting to go through it.

   There's actually a commercial product called VoleBloc aimed at doing just this. The product is fragments of slate that you use to make a buried "moat" around the plants you're trying to protect.

   The company recommends digging a trend 3 to 4 inches wide and 10 to 12 inches deep all around the plants. Then fill the trench with 100 percent VoleBloc and add 1 to 2 inches over the soil surface as a mulch.

   Here's a company link for more information:

   It used to be in garden centers, but I haven't seen it any lately.

   The main downside is the expense (not to mention the work). Depending on how big of an area you're protecting, you'll go through a lot of bags of VoleBloc trying to protect your hostas. It's not particularly cheap either.

   Chicken grit is also jaggy and less expensive. It's usually sold at farm stores. Gravel also should work, and The Espoma Co.'s Soil Perfector is another commercial bagged product made of ceramic fragments that also may work. Basically, the jaggy the material, the better it should work.

   If you can't get rid of the voles by turning loose a cat or trapping them (snap traps to kill or Havahart cage traps to capture), another option is planting your hosta in sunken plastic pots. The pots will stunt growth and prevent roots from spreading as they should, but constricted roots are better than no roots. And recycled pots -- like the kind that shrubs come in from the nursery -- are a lot less expensive than any of the jaggy material.