you know that fall is still egg-laying time for slugs? We tend to forget
about them as the hosta leaves change color and head into dormancy. The
slugs will be active until the soil temperatures reach freezing, when
they will go into hibernation until the spring thaw. So, until that
happens, they will lay eggs. Mating will occur from August until
mid-October with eggs laid about 30-40 days after that. Look for 1/8 to
ľ inch sized gelatinous clusters of about 20-30 spheres. Older slugs
will lay larger quantities. The eggs may be hard to see as they can
reflect their surroundings. When the eggs are near hatching, the spheres
may become cloudy. Slugs love those piles of leaves, damp from heavy
dews and fall rains. Look for them under anything that will keep them
cool and moist. Other favorite places will be flowerpots, boards,
cooled compost piles, at the edge of large rocks or under mulch.
So the big question is-what to do?
Eliminate their favorite spots.
Clean up the old hosta leaves and other debris. Turn the compost
pile to make it too hot to be attractive for them. Check under
those flowerpots before you store them.
||Set a slug trap. They are attracted
to any fermenting food: beer or a mixture of sugar, yeast and
water. Sink a tuna can with the rim 1Ē above ground level so they will crawl
in and drown. If you put it flush to the ground you run the risk
of drowning ground beetles, which are a slug predator. Colorado
State U. Entomology Professor Whitney determined that their
favorite types of beer were Kingsbury Malt, Michelob &
Budweiser. Empty often. Replace beer weekly. Commercial
slug baiting stations are available. If you leave a flat board on
the damp ground, you can scrape them off in the morning.
||Go on a slug hunt. Late at night or
very early in the morning, grab a flashlight and bucket of soapy water
to drop them into after hand picking. Slugs are nocturnal and love
to hit the all night hosta diner. Watch for the little ones. Like
teenagers, they are voracious eaters. You can even use a handheld
vacuum to suck up the little pests, but you may want to warn the
next person to use it.
||Encourage a predator to hang out in
your garden. Toads, turtles, owls, Mourning Doves, and Robins love
slugs. There are also some predators that we may not be too
thrilled encountering in the hosta bed that also feast on slugs:
black ground beetles, opossums, shrews, wild turkeys, chipmunks,
skunks, moles and Northern Ringneck snakes.
Phosphate baits - Slug bait pellets
made from this can stop slugs without poisoning birds, small pets,
humans or earthworms. Though they are not sure exactly why, iron
phosphate inhibits the slugs from feeding, and it is actually
good for the soil. It is sold under the names of Sluggo,
Es-car-go, and Saferís Slug & Snail Bait.*
baits - This is a molluscicide,
which means it is a poison that kills slugs, and can also be purchased
in a form to spray on the hostas. It is very effective for killing
slugs, but also kills earthworms and other things with which it comes in
contact. Great care in handling, application and storage
must be observed.**
Solution - A solution of
household ammonia (1 part ammonia: 5 parts water) in a spray bottle
with the nozzle set on a direct stream and sprayed directly on the
slug will kill it in a few seconds. This solution will not harm
Copper tape placed around
the hostas as a barrier repels slugs because as they slime across it, it causes
a toxic reaction like an electrical shock. However, if they find a leaf
lying over the barrier, they can get in. A product called Slug
de-Fence is composed of a low density polyethylene plastic and
vacuum grade table salt. It repels the slugs unless they try to
get over it, and then the salt gets them, but it may also look like you tried to wrap your plants with
little trash bag fences.
Materials - Eggshells,
coffee grounds, sand, cedar shaving, hair or ash are abrasive
materials which may be placed
around plants which will scratch the slugs' bodies causing them to
dehydrate. Diatomaceous earth can also be used, but it is a very
fine powder and you must wear a mask to keep from inhaling it.
These products must all be kept dry to work, and they must be
reapplied after a rain.
Controls - In Europe you may
purchase the parasitic nematode Phasmarhabditis hermaphrodita,
which is naturally occurring in their soil. This is a microscopic
worm that enters the slugís body through natural openings and
releases bacteria that multiplies and kills the slug in 4-16 days.
It does not bother earthworms. It also has the ability to recycle
and become part of the ecosystem in the absence of a host, which
would make it good for long term management. It is marketed under
the name Nemaslug, but donít try to add it to your Thompson
& Morgan order just yet; itís still illegal here.
Agricultural scientists collaborating from Ohio State U. and
Purdue U. are doing parasitic nematode research to help protect
crops in no-till fields that are most susceptible to slug damage.
They are also evaluating the American parasitic nematode cousin,
but so far none is as effective at the European relative. They are
compiling data showing the safety of importing nematode Phasmarhabditis
hermaphrodita into our soil.
Author Bio - Mary moved to Lowell, Indiana in 1988 when
she married her husband, Neal. Her in-laws gave her her first
hostas plants, although they called them funkia. Later she and
Neal happened on Dogwood Farm Nursery and were hooked. They
now have over 700 varieties.
| She is currently a
member of the NW Indiana Hosta Society, the Indianapolis Hosta
Society, the Great Lakes Region Hosta Society, and the
American Hosta Society. When NWIHS was new, she held a number
of positions, but now serves only as newsletter editor. In
2009 she accepted the position of Newsletter Editor
Coordinator for the AHS, assisting the local hosta clubs
across the United States in exchanging news, ideas, and
She attended her first AHS Convention in
Cleveland (2005) followed by Indianapolis and St. Louis. Hosta
College in Piqua, Ohio, is an annual treat each March when
nothing is green in NW Indiana. Her favorite hosta in her
collection is 'Simply Sharon' and she is continually amazed at
the variations that appear each year as the new hostas are