Garden Column for the Salisbury Post
July 25, 2003
“My
hostas are complety gone and it appears something is eating the roots” is a
common complaint I have heard for the past few weeks. Voles are causing damage
to a number of plants including hosta and some shrubs. It is difficult to
imagine a mouse-like creature, weighing less than an ounce, could cause so much
damage.
Voles
look much like a small mouse, with the exception of a stubby tail, shorter than
its hind legs. Damage from the
reddish-brown rodent can be very slight or quite extensive, destroying
entire landscape plantings.
Voles
are often confused as moles, however, moles feed on live immature insects in the
soil, whereas voles feed on plant tissue. Most
complaints have been from vole damage to dwarf nandina, hostas, canna lilies and
tulip bulbs. Once these rodents
locate a reliable food source they remain until the food supply is exhausted.
Female
voles produce six litters averaging three voles per litter.
Young females reach maturity at 38 days, remaining fertile for at least
18 months. Large vole populations may live in an area as small as 1000 square
feet.
Damage
by voles is easily recognized. Gnawing marks on the tree or shrub can be located
just under the soil line. Shrubs are
often gnawed in two, while trees, especially apple trees, are girdled.
Girdling may not kill trees outright, but offers areas for diseases and
insects to penetrate, reducing yield, gradually killing the tree. Hostas may
have a hole near the side of the plant with the roots and stems completely
removed.
Trapping
with snap-type mouse traps is an effective method of controlling voles, although
it takes some skill and persistence. Excavate
down into the run and place the trap, and a small piece of apple as bait, at a
right angle to the run.
Bend
a piece of cardboard to form an arched roof over the trap so that the spring
clears the shingle. It is essential
that the shingle make a tight fit to the soil to eliminate light.
Set snap traps at ten foot intervals throughout damaged plantings,
checking them daily, resetting until no voles are caught over a one week period.
Large landscaped areas can be concentrated to a particular plant bed,
achieving control at that location, then move trapping efforts to other problem
areas.
Rodenticide
such as chlorophacinone, are formulated as paraffinzed pellets (Rozol Rat and
Mouse Killer Pellets) that can be used by homeowners.
It is safe and effective when used according to the label. Read all
pesticide labels carefully before application.
Pets should be prevented from coming into contact with this pesticide.
Place
two tablespoons of pellets under a covered runway actively used by voles.
Place bait at ten foot intervals in the infested area. Repeat the process
in three weeks. Use an apple as bait
to confirm control. Both bait and
traps may be used at same time.
PermaTil,
a soil amendment, claims when used as a physical barrier, prevents voles from
damaging bulbs and shrubs. The rough edges of the amendment wards off the pest.
PermaTil is a soil additive normally used to amend clay soils in shrub and
flower beds.
Darrell
Blackwelder is an agricultural agent in charge of horticulture with the North
Carolina Cooperative Extension Service in Rowan County. For archived garden
columns or other information, visit the Rowan County Master Gardener web site at
www.rowanmastergardener.com ,
e-mail Darrell_Blackwelder@ncsu.edu
or phone at 704-633-0571.