Problems / Solution Advice...

Moles

The most often asked question and complaint at Greenscape Gardens centers around moles.  A little background information concerning moles is necessary to justify this annoying nuisance.

Moles mainly feed on earthworms.  Grubs and other small insects are a minor food source.  During their burrowing activities in quest of food, they may injure plant roots but normally this is minor, but they do leave those annoying mounds and ridges that disfigure lawns. 

Moles are active all year, but most active during the early spring on cloudy, damp days or following rain showers.  When the ground surface becomes frozen, they use deeper burrow’s  Daily peak activity periods are during the morning hours, although they may be seen working off and on throughout the day and night. 

Mating occurs during February and March, with a single litter of three to five young born later in the spring.  Young moles grow rapidly and leave the nest to fend for themselves at about one month of age.

Runways:  Two types of runways are produced by moles, surface runways and deep runways.  Surface runways are commonly seen as the raised ridges running through lawn areas.  These runways wind around with no apparent “direction plan”.  Surface runs may be used daily, revisited at irregular intervals, or used only once and then abandoned.  They connect with the deep the deep runways which are located between 3” and 12” below the surface.

Deep runways are usually main runways, since they are used daily as the mole travels to and from surface tunnels or the nest.  The soil excavated from the deep tunnels is deposited on the surface through lateral tunnels in volcano-like mounds.  Very little, if any, soil is excavated in mounds as a result of the production of surface runs.

When concrete, hard surfaced areas or other man made borders are within mole active areas, the moles tend to construct their main runways following these artificial borders.  It is also common for the main runs to be constructed in a direction that follows the woody edge perimeter of a field.

The number of mounds or surface ridges seen in a yard is no indication of how many moles may be present.  One acre of land will not support more than six moles, although sometimes as many as twelve moles have been trapped in one year.

CONTROL BY TRAPPING

The keys to success are patience, practice and persistence.  Moles are shrewd animals; they will evade, spring, or go around any improperly set traps.  Place traps carefully, and keep trying until experience leads to success.

Trapping is easiest and most effective during the spring and fall, when mole activity is at a peak.  For successful trapping, it is essential to locate the main runways.  Usually, if a runway takes more or less a straight course for some distance or seems to connect two runway systems, it is likely to be a main runway.  Determine active surface main runways by poking small holes with a broom handle into the runway at several locations throughout the runway system.  Moles will repair these holes within a few hours to 24 hours.  Runways unrepaired over a longer period of time are not worth trapping. 

Unless the mole activity is extremely light, more than one trap should be used.  Do not depend upon a single trap to do the work of a dozen.  If activity is heavy or the area is large, it will be necessary to use multiple traps.

moles3There are two commonly used traps—the harpoon trap and the scissors-jaw trap.  The harpoon trap works most effectively in our area.  To properly set a harpoon trap on  a surface run, first lightly press down with your foot a small section of an active runway so that the runway is collapsed ½ of its original dimension.  (Do not push down the ridge completely).  Raise the spring of the trap and set the safety catch.  Then, push the supporting spikes into the ground, one on either side of the runway until the trigger pan just barely touches the depressed tunnel.  (Be sure the trap is centered over the runway, and the supporting spikes do not cut into the tunnel below).  Next, release the safety catch and spring the trap to ensure that the prongs will penetrate smoothly into the tunnel.  Finally, reset the trap and leave it, taking care not to tread on or otherwise disturb any other portion of the runway system.

Trapping results can sometimes be improved by setting traps in the deep runways used by the moles on a daily basis.  If a trap fails to make a catch within 3 days, it should be moved to a new location.  “Remember, for best results; keep human scent off the trap”.

moles4

INSECTICIDES

Sometimes mole control can be achieved with insecticides to eliminate grub and earthworms.  Most chemicals employed for grub control have little effect on earthworms, a common food source.  Thus, controlling grubs in the lawn may not solve the mole problem.  In addition, it is important to remember that the presence of moles does not necessarily indicate that grubs are present in the lawn.

BAITS, CASTOR OIL, AND GAS

Another means of controlling moles is spraying the lawn with a castor oil extract.  This method is effective for 2 to 3 months.  It normally doesn’t eradicate the pest but simply makes them relocate to other areas.   

Baits are sometimes used, but will give erratic control because of the mole’s preference for a diet of earthworms and insects.  Gassing tunnels is often ineffective because the gas may escape through the thin sod above the tunnels. 

WHAT DOESN’T WORK

  • Chewing gum in the run, moles feed on actively living organisms.

  • Human hair in the run

  • Poison peanuts, once again they feed on living organisms

  • Wind daisy, a gaudy lawn ornament (highly ineffective)

  • Flooding the runs is seldom effective.

POINTS TO REMEMBER

  • The presence of moles does not necessarily indicate that grubs are present in the lawn

  • The best control method is by trapping.

  • For best results, be sure the traps are placed in active runs.

  • Keep human scent off the traps.

  • Patience, patience, patience.