I have been using cardboard with mulch in my fruit orchard. There now seem to be a lot of black voles running around. I already have hardware cloth around the trees, but am concerned about my berries. I remember reading on Garden Web about a method of trapping using buckets of water and a dowel or bottle above it that would cause a critter to fall in and drown, but don’t remember the details or if it just works on mice. Has anyone found an effective way to drown voles, or must I invest in a bunch of spring traps and peanuts placed under trays to protect the birds? My acreage is not at my house, so a cat wouldn’t work, and I don’t want to use poison.
We have what I call ‘cocktail’ voles. In the evening my husband and I go down to the orchard for a glass of wine. The voles come out about 6:00 every evening. Last night I saw a very large black cat running out of my orchard and we were going in. Lo n’ behold, from three cocktail voles we’re down to one! More are probably hiding but I’m letting a neighbors cat take care of them. I just don’t like it when they toss them in my small pond.
In my veggie garden I actually tried a version of the Caddie Shack method. Would not recommend it for an orchard, but it was informative about the tunnel linkage between the exits!
I’m a bit slow here this morning. What’s the Caddie Shack method? I’m picturing you putting something down a hole and accidentally blowing up something you didn’t intend to. 
I think they used propane in Caddy Shack against a groundhog. Last year I had multiple perfectly round holes with no exterior dirt show up in some of my raised beds and in the paths between. I have access to lab ethanol, so I mixed up some of that with some gasoline and poured it down several of the holes. A single match at one hole resulted in an interesting pipe organ/geizer effect where flames came out of most of the holes and did a little dance as they hit combustibles and the draft changed I am guessing. I am fairly sure I must have gotten some of them as the holes were not reopened after I plugged them. OTOH the buggers later got my sweet potatoes in a bed I did not treat for obvious reasons.
Everything loves sweet potatoes, both the leaves and the tubers. Last year I was glad they were far from the house. Caught a rat that was devouring tubers. It was the only thing in the garden the sucker was hitting.
Closely mowing near and around your berries will help. Eliminate the areas they harbor within about twenty yards of what you want to protect. They live under wood and brush piles, tarps on grass, tall grass and weeds. They seem to tunnel only a certain distance from the places they find good cover like I described.
Swamps, I can’t mow around them, because they are in a former vacant pasture with cardboard laid over a large area and then covered with semi-decomposed arborist chips. Beyond that is tall weeds. So the voles hide under the cardboard. I want to thin the herd before they cause damage. I guess I will buy some traps and also experiment with some sort of water bucket traps. I wonder if I dig the buckets partially into the ground and then put a dowel across with a piece of slippery pcv pipe or something similar with some peanut butter on it, if the voles would fall into the water? Hopefully a skunk could jump free if it tried to get the peanut butter.
I’ve dealt with voles for years…they seem to always be some around and the population varies year to year. I’ve killed as many as 20 or more in one summer/fall to as little as 1 or 2…this past year was pretty good although i’m starting to see them now. This time of year is when they are on the move. They like to get into the garage and try to build toasty little homes in my work benches. I usually get them with kill traps, but not having much luck with the peanut butter right now. I think they have enough food that they aren’t interested or just too smart. I may build one of these drowning contraptions. I dislike rodents in my garden. A good reason to keep the lawn mowed and nothing touching the ground. They love tomatoes so keep them high. They also can climb.