"You don't have a slug excess, you've got a
Bill Mollison Permaculture expert
Slugs are hermaphrodites: they all
have male and female reproductive systems. They can
stretch to 20 times their normal length enabling them to squeeze through
tiny openings to get
at food. Slugs can follow slime trails they left from the night before. Other slugs can
also pick up on this same trail creating a slug network to the host plants! Slugs and
snails actually both have shells. Slugs' shells are much smaller and not visible as they
are underneath the flesh on their back.
Slug eggs are in the soil just about everywhere. They can be there for years and then
hatch when conditions are right. It actually takes moisture to allow them to hatch. To
identify the eggs look for oval shaped white colored eggs in moist soil areas, under
rocks, and boards. Eggs are laid in clusters of two dozen eggs each. The adults also
overwinter in the soil and can live for many years. In the Pacific
Northwest they have banana
slugs which are bright yellow, grow to 8 inches with some up to 18
There are at least 40 species of slugs in the US. Some of the more common
Grey field slugs: (Derocereas reticulatum): this is about
1.5 inches in length, grey to tan in color with dark spots and has a light colored belly
with a dark streak down the middle. Its' preferred foods are lettuce and cabbage. However
they will go after anything.
Black slugs: Large up to 6 inches long with rough bumpy
skin and a light colored foot. They are mostly black in color but can also be brown or
red. Prefers tender seedlings leaving more mature plants alone.
Common garden slug: This probably the most often observed
slug. One inch long, dark skin with a lighter stripe along the side. The foot can be
either red or yellow. It can damage stems, roots and slither up plants causing much
damage. It borrows in the soil to feed on root crops.
They can truly do a lot of damage to your plants. They like damp places,
feed at night and prefer tender new growth, seedlings, lettuce, delphiniums and French
marigolds. Slugs really go after hostas. These tips should help all of us hosta enthusiasts to keep them looking their
are some ways to do battle with slugs:
following are all suggestions and may or may not work for you
General Slug Tips
Try our Golden Harvest Natural Fertilizer
It helps your plants to resist slugs &
Getting off the slime: If while dealing with slugs you get the slime on your hands or anything else here is a
great way to get it off! Pour a little cheap white vinegar on your hands and wash it off
with lukewarm water. Really cuts that slime! Repeat if needed.
Cultivation: Spring cultivation of the soil where practical will help to kill hibernating slugs and
Seedling Protection: Protect your seedlings with 2-3 litre plastic soda bottles. Make sure no slugs are
around the seedlings first. Cut the bottoms out of the bottles, sink them into the soil
around the seedlings and remove the caps. You can reuse them over and over too.
Weed Patrol: Be persistent in hoeing weeds and you will be breaking up clods of soil that slugs like
to hide under and you may expose their eggs which you can then smash or whatever.
Mulch: Keep mulch pulled back from the base of your plants. Consider waiting to apply mulch
until the soil temperatures have warmed to above 75F.
Garden Debris: Keep all decaying matter cleaned out of your garden beds.
Clear all dead leaves and debris from the garden on a regular basis and put it in the
compost pile which is best located in an area away from the garden.
Shrub Trimming: Shrubs with branches that rest on the ground, against fences or buildings should be
kept pruned up and away from surfaces. Keep the old leaves and such cleaned out. By doing
this you will have destroyed yet another slug haven!
Chopsticks: For handpicking use chopsticks to make it less disgusting.
Slug KaBobs: Keep barbecue skewers stuck in the garden at random. Your weapon is at hand to impale
Slug Haven: The shaded areas beneath decks can be a slug arena: keep them weed and litter free.
Try lava rock as a barrier in areas where plants need
protection. We have heard from many people who say it works very
Use horseradish roots and geranium leaves as barriers. Does this work?
If you have access to a sweet gum tree (Liquidambar) the spiny fruits it produces make
a good slug barrier. The American Sweet Gum tree (L. styracflua) is hardy from zone 1 to
Use the lint from your dryer as a barrier. If you are concerned about any chemicals in
the fabric softener do this instead: add 4 ounces of white vinegar to the final rinse
water in the washing machine. Your clothes will be static free. There will be no vinegar
smell as the odor completely evaporates. No kidding, this really works great.
Use cedar, oak bark chips or gravel chips which will irritate and dehydrate them.
Try a barrier line or an overall sprinkle of powdered ginger.
Use wood ashes as a barrier around plants, however try not to let the plant come into
contact with the ashes. The ashes act as a desiccant and dry the slugs up.
Shingles or Sandpaper: Get rid of slugs in the infested area then lay a barrier of roof shingles around the
area to keep slugs out or use a circle of sandpaper.
Spread well crushed eggshells around the plants. The calcium released from the
eggshells is an extra benefit that "sweetens" the soil. The sharp edges of the
shells will kill slugs. Most folks report that this does not work
Sprinkle a line of lime around your plants. A pile of unaged animal manure has an high
acidity and provides a slug breeding haven leading to the assumption that slugs and
snails are more of a problem in acid soils. By applying lime we sweeten the soil making it
more alkaline and deterring the slugs. Obviously this won't work around plants requiring a
more acidic soil.
Talcum powder or diatomaceous earth work as
barriers but must be replenished after after rainfall or watering.
Hardware Cloth: On raised beds staple strips of hardware cloth on wood bordered beds. Extend the cloth
about 2 inches beyond the edge making sure the sharp points will be encountered by slugs
trying to climb over. It rips them up. You can also use aluminum screening material in the
same manner. You can push the barriers directly upright into the soil for borderless beds.
Copper Strips: The use of copper strips as a barrier will give slugs a jolt of electricity. The metal
ions in copper are what repel slugs. There are mixed reports on just how effective this
is. One good way to try copper strips is to make a circle of the strip around just the
plants you want to protect, remove slugs first. Easier too. Copper sulfate and similar
copper based products may also work for the barrier method.
Herbs: A mulch made of stems and leaves of strong smelling herbs like wormwood, mints, tansy,
lemon balm along with conifer twigs mixed in will help stop slugs and other pests.
Hair and Fur: Use a barrier of hair or fur to entangle slugs. Gross and effective. An additional
benefit from using hair is that it supplies some nitrogen to your plants! Human hair, pet
fur and horsehair, all will work.
Prunings: Another possibility is to use prunings from raspberries, blackberries etc.
Anything with fine, sharp stickers may help.
Quack Grass: Quack Grass (Agropyron repens,
family Gramineae), damages the nerves slugs use for feeding. Chop it up and use it as a mulch.
Make a tea by cutting it up, soak in 1 quart of warm water for 24 hours, then use as a
barrier spray on soil. Don't spray directly on plants. The use of
Quack Grass has, personally, worked very well for us. See more on using Quack Grass for
Oak Leaves, Lettuce and Cabbage: Using oak leaves as a mulch deters slugs, so does seaweed if you have access to some.
Also of interest is that red oak leaf lettuce is not bothered by slugs or snails! Red oak
leaf is tasty and can take some hot weather. Also of interest we observed that slugs were
all over green cabbage, but the red cabbage was left alone!
Coffee Grounds: Used coffee grounds spread around susceptible plants may work.
Epsom Salts: Epsom salts sprinkled on the soil will supposedly deter slugs and also helps prevent Magnesium
deficiency in your plants. Magnesium helps to deepen color, thickens petals and increases
Oat Bran: Scatter oat bran on the soil to kill slugs and snails.
Builders Sand: Try barriers of builders sand which has a sharp texture.
Nut Shells: Ground shells of filberts, pecans and walnuts may work, if you can find a source or grind
Cocoa Hulls: Cocoa shell mulch may work as a slug deterrent as well as supplying nitrogen to the
soil as it breaks down and it suppresses weeds too! We've had
mixed reports of people using cocoa shells for slug control. Some
folks say it works fine to fairly well and some say the slugs love
it so much that they are all over it and their slime creates a
hard crust on top of the mulch! We will suggest that you buy a
small amount of cocoa shells and try it out first.
Warning: Dogs may be attracted to and can eat cocoa hulls
which can be fatal!
Rosemary: Sprigs of rosemary scattered around repel slugs and are refreshing with their piney
Mullein & Slugs: (click here for our test
report) Fresh or dried mullein (verbacsum) leaves placed around vulnerable plants and
areas repels slugs and snails. Mullein is also a nice tall accent for use as a background
Pine Needles: Try a mulch of pine needles which works well around strawberry plants.
Plants slugs generally steer clear of:
||Red oak leaf
(Swedish in particular)
Plants like chicory and endive are virtually slug proof.
Predators of slugs include: Ground beetles (particularly carabid
beetles), turtles, toads, frogs, lizards, rove beetles, salamanders, lightening bug
larvae, turtles and garter snakes.
Island Red hens are great slug hunters, they get virtually all
slugs and snails they can find. A big plus is no crowing from
hens! Other slug hunters include blackbirds,
crows, ducks, jays, owls, robins, seagulls, starlings and
thrushes,The appeal factor to all these creatures is due
the fact that slugs are pure protein. Yummy.
Nemaslug: (currently not available in the USA) There is also a
predatory nematode, Phasmarhabditas hermaphrodita, that is effective against slugs. They
are being mass reared apparently in England but are not yet sufficient in production to be
used widely. They are watered onto the soil and will kill slugs for up to six weeks. The
water and nematodes leach down into the soil where 90 percent of slug populations live. It
is this underground population of slugs that the nematodes attack and kill. The nematodes
should be applied anytime between April and October when the temperatures are milder for
the best control. Soil must be kept on the moist side for the nematodes to live. These
nematodes kept in a sealed bag and refrigerated will last up to two weeks. You can do an
initial treatment, then retreat with the remaining stored nematodes for two additional
weeks. This would give you two months of control from one batch.
The only place we know of currently to sell the nematodes is the Chase Organics
gardening catalog available through the HDRA in the UK. The product is called
Supplies are limited. The catalog is available to everyone, but they cannot sell Nemaslug
to the USA.
Henry Doubleday Research Association in England
TEL \ FAX: (01622) 639229
Note: There is a predatory snail known as Ruminia decollata that will feed on those
brown garden snails. However they will apparently kill native snails.
Sprays and Dusts
Isopropyl alcohol spray will dry them up. Mix 8 ounces of 70% rubbing
alcohol with 1 quart of room temperature water and spray. Be careful as some plants are
very sensitive to alcohol sprays.
Wormwood tea from artemisias works to repel slugs, snails, and
crawling insects. Wormwood actually produces a botanical poison that is fairly potent.
This can be good to use on the soil in the fall to kill slugs that have burrowed into
their overwintering places.
Talcum Powder or Flour: Dust them with talcum powder or flour.
Buttermilk spray forms a crust on them doing them in.
To make: Mix 8 ounces of flour, 2 ounces of buttermilk and 1 gallon of cool
water. Spray those suckers! If you get it on your plants, rinse off after 24 hours.
Ammonia spray: Slugs like to lay eggs on the crown of hostas and
then the tiny baby slugs do tremendous damage as the new growth is emerging. When
using this spray on hostas it may be advisable to rinse off their leaves with water about
an hour after spraying to prevent leaf burn. Some of our readers report that they do not
rinse the leaves off and have no problem with leaf burn. You will need to see how your
plants react to this. Make your spray as follows: mix 3 ounces of ammonia with 16
ounces of water. Cheap source of nitrogen too.
Horseradish spray: Bring 3 quarts of water to a boil, add 2 cups of
cayenne peppers, a 1 inch piece of chopped horseradish root, and 2 cups of packed scented
geranium leaves, any kind. Let mixture steep for 1 hour, cool, strain and spray.
Watering the soil with liquid seaweed extract has just enough of an
alkaline effect that slugs hate, but not enough to significantly change soil pH. Calcified
seaweed meal contains tiny shells which will cut and desiccate slugs.
Iron sulfate will kill them on contact. It is poison to slugs. Mix 2
teaspoon of iron sulfate with 2 quarts of water. Use in a pressure sprayer to spot spray.
Wood ashes and soot kill slugs quickly especially in drier weather as
will hydrated lime.
Quassia: Made from the chips and shavings from this Latin American
tree. Quassia produces one of the safest botanical pesticides and has been used
medicinally by herbalists. It will not harm ladybugs or bees. Quassia chips can be
purchased at natural food stores.
More on Quackgrass for Slug Control
To protect established perennials in your yard, surround them with dried and finely
chopped quack grass (Agropyron repens, family Gramineae) leaves and roots. Apparently the roots are more toxic to the slugs
than the leaves! Use no more than 2 ounces of dried quack grass per 10 square feet. Too
much could inhibit the growth of your plants. Note: quack grass does have some herbicidal
properties to it.
Quack grass cake: Use this around your tender seedlings. Mix together
1 ounce of corn bran, 3/4 of an ounce of powdered milk, 1 ounce of cornstarch and 16
ounces of beer. Combine all of these with 8 ounces of dried quack grass to make a thick
paste that will form pellets. It goes on to say you should run this through a meat grinder
to create pellets which you then allow to air dry. Spread the pellets around the
boundaries of the seedling bed. Slugs will be attracted to the beer bait and eat the toxic
grass! Sounds like a plan.
It was found that within 30 minutes of spreading these pellets in some fields in New
York slugs began to feed on them. The results: in area where slugs were numbering at 78
per square meter following a heavy rainfall, the number dropped to one slug per square
meter 30 minutes after the pellets were applied! Impressive. Pellets remained effective
for about a week.
Slug Trap Methods
Trap Crops: Use beans, horseradish leaves, comfrey leaves, calendula, lettuce,
marigolds, plaintain (yes, the weed) and zinnias as a trap crop for slugs.
Black Plastic Bag Method: If you have a slug
attack in one area in your garden this is a quick method to reduce the
numbers . Take one black garbage can liner and place on the ground in
between your tender plants. Then place two heads of letuuce
which are well past their prime. Add two tea cups of breakfast bran
and pour a cup full of beer (bitter is best) over the lettuce. Leave
over night with the top open and check in the morning. Slug should
have climbed into the bag over night and as the sun comes up in the
morning they will stay in the bag for shelter in the bottom of the
bag, You are ready to get rid of them and repeat the process if
Cabbage Trap: Cook cabbage leaves until soft,
drizzle some butter or lard over them. Place them in slug prone
areas. Within several hours the leaves will be swarming with slugs.
Collect and destroy.
Dog Food: Using dry dog food draws slugs like flies. Simply take dry dog food and put
enough water on it to make it slightly soft. Place it in piles in slug infested areas.
Check later in the evening and dispose of bait and slugs however you want.
Beer or yeast traps: Traditional traps
that seem to work well for some and not at all for others. Sink containers of beer
or yeast and water at one inch above ground level in the garden to entice and drown
your prey. Empty traps as needed. For the yeast trap use one package of yeast to 8 ounces
of water. Mixing rum extract with water may work also. Prop some "escape" twigs
in the containers so beetles can climb out.
Grape Juice: A new rendition on the beer trap is to use grape juice. For some reason slugs really
have a taste for this. Use just as you would in the beer method and buy the cheapest
grape juice you can find!
Honey-Yeast Bait: Here is another mixture for sunken traps to try: In your container mix together the
following ingredients: 1 tbsp. of brewers yeast, 1 tbsp. honey, 1 tbsp. cooking oil and 12
ounces of water.
Beer Batter Bait: Mix 2 tablespoons of flour with enough beer to make a thick batter. Put 1 teaspoon of
this in a small paper cup and lay the cups on their sides around your plants. Slugs will
flock to this, get snared in the flour and die. When the trap is full toss the whole thing
in the compost pile.
Slick Containers: Try filling the sunken containers with soapy water or simply grease the insides with
petroleum jelly so they can't slime back out.
Gutter Trap: Place sections of aluminum gutters in slug prone areas. Rub them with a bar of soap to
coat the insides which will trap the slugs. Empty regularly into a bucket of soapy water
to kill the slugs.
Pop Bottle Traps: Make traps to collect slugs out of those 2 liter plastic pop bottles. Cut the
bottle in half. Invert the top part into the bottom part to create a no escape entryway.
Be sure to leave enough leeway where the top of the bottle is for the slugs to enter. To
up the stakes put this mixture into the traps: 12 ounces of corn syrup, 1 tbsp. lemon
juice, and 16 ounces of water. Put in a saucepan, bring to a boil stirring until the sugar
is dissolved. Let this come to room temperature and pour into your traps. You can also try
this mixture as a bait in any other traps you come up with.
Veggie Baits: More baits you can try are lettuce, cabbage, turnips and sliced potatoes.
Comfrey (See: Symphytum peregrinum): This
perennial is a preference of slugs and can be used as a trap. Comfrey is considered to be
an invasive plant, however it has so many uses for the garden and medicinally that it is
worth having around. Comfrey has more protein in it's leaves than any other vegetable
perhaps explaining its appeal to slugs. This can also be tried with horseradish leaves.
Technique: In early spring pick a bunch of comfrey leaves, allow them
to wilt. Place them in the center of the planting area. Slugs will come
the pile networking more slugs every evening. After about a week remove as many of the
slugs from the pile of leaves and dump them into a bucket of soapy water. Dispose of them.
Allow the remaining slugs to build up in the pile for a few more days then dispose of the
whole mess by incorporating it into your compost pile. After this you can place a barrier
trap of comfrey leaves in a border around your garden to trap any migrating slugs that are
left. When sufficient control has been reached, again compost what is left.
Use overturned grapefruit or orange rinds for them to collect under during the day.
Squash the whole thing and throw it in the compost pile.
Scraps of wet carpet spread around the garden will draw slugs like a magnet! Scrape off
and dispose of the slugs, and reuse.
Old pieces of flat lumber are a good trap. Reuse until the lumber starts to fall
apart, then recycle it further by adding to the compost pile.
|Slugs Prefer.....In 1987, Colorado State University
Entomology Professor Whitney Cranshaw had his students conduct a test for the beverage
most favored by local slugs:
Here's the results of that experiment. Note Budweiser was chosen
as the test standard and the number of slugs choosing bud
represented one Bud Unit Kingsbury Malt Beverage was the
you live out West look for Dr. Cranshaw's excellent book
"Pests of the West."
|Fort Collins CO tap water
|Gallo Pink Chablis
|Kingsbury Malt Beverage
|Sugar-water and yeast