We have been plagued with moles for several years. We have had lawn servives apply grub control and have used sound and vibration devices. Please help.
Based on research, grub control products have been proved to be ineffective at discouraging moles, because the moles simply eat something else besides grubs. Also, we have no research that the sound and vibration devices work.
Moles can be very beneficial to lawns. Besides eating pests, they aerate the soil in a way that humans cannot, and this gets oxygen to plant roots, which they must have. Moles are very solitary. Usually only one mole moves into a yard. It stays a year or so then suddenly leaves.
The only fool-proof way to get rid of one is with a harpoon trap. You must first tamp down all tunnels. Read through our website info, which explains this: http://extension.umd.edu/hgic/moles
Although an amateur, I would like to add this alternative perspective which disagrees with the professional, apparently official, position of HGIC. I have dealt with moles and voles for over 20 yrs and believe that ECN's opinion may be from an academic perspective rather than real life experience.
Fact 1: Moles tunnel very close to the surface so create an extended air pocket where the grass roots are. Guess what happens to roots when in air rather than soil, which is occasionally moist? The roots die so does the grass.
Fact 2: I don't know the science behind it, but along all the tunnels where the grass died, that area was quickly filled in with moss. When moss has a foot-hold, it is very difficult to remove.
Fact 3: Mole tunnels pop up well above the ambient soil level, so disrupt desired mowing height.
Fact 4: Moles eat earth worms which are beneficial.
Fact 5: While moles do more direct damage in lawns, their tunneling attracts
voles, which are extremely destructive to our gardens by eating roots of small trees, perennials, bulbs, etc. (so killing them); but during snows will also
kill small trees by eating bark.
FYI, I have tried all known "folk remedies" including ultrasonic vibration,
windmill vibration, and juicy fruit chewing gum, all to no avail.
Although I respect ECN's academic credentials and experience, her opinion
is quite contrary to my experience. I hope that some day they conduct some scientific experiments or observations. Good luck from another MD gardener.