Those tiny (and sometimes not so tiny) creatures that wreak havoc in your garden. They munch the lettuce and the leaves of flowers, decimating newly planted seedlings overnight. With their slime and their capacity to eat vegetables, they alternately disgust and fascinate us.
Slugs have an important role in forest ecosystems, though. Just like worms, they are skilled at turning just about anything into soil. Yes, they may be eating machines, but in addition to green vegetation they also eat old leaves, mushrooms, dead animals and even animal poop. Yes, slugs eat it all, and we should thank them for cleaning up the forest floor, even as they clean out our gardens. However, this is one case where they do more harm than good, in the eyes of gardeners looking to grow healthy and strong flowers and vegetables.
So how do you deter slugs and their mollusc cousin, the snail? Why, place a natural "keep out" sign between the forest and the garden beds! Organic pesticides and other insect control methods have a role to play in deterring slugs from eating your plants.
Make Slugs Feel Less At Home in Your Garden
The first "keep out" method in your garden is to create a habitat that is unsuitable for that animal. Slugs love damp, dark places. Rotten leaves, rocks, and old bricks are perfect hiding places for slugs. They dislike warm, dry places.
If your garden is damp, dark, and full of slug hiding places, make it more open, with fewer areas for slugs to hide. If you mulch all summer long, you may have to remove it until you get the problem under control. As a proactive approach, remove or turn over fall and winter mulch and other garden debris to expose slug eggs to the air and to predators.
Avoid watering your garden in the evening. This is when slugs come out to feast. By watering in the morning (which is the best watering practice anyway), the ground will be dry by the afternoon, and slugs will find the soil unpleasant by the evening.
If you prefer to mulch, add whole seaweed to your garden. Not only is seaweed a great fertilizer as it decomposes, it has salt (as seaweed comes from salt water). The salt concentrations are at a low-enough level to not make the soil toxic, but high enough for slugs to avoid. Also, as the seaweed dries out and decomposes, it forms sharp ridges, dangerous for the soft bodies of slugs. Remember, if you do mulch (using seaweed or not), keep an area away from your plant stems.
You can also invite predators and change the balance of your garden food chain.
Natural Predators: Who Eats Slugs and Snails?
Beetles love to munch on slugs, and they enjoy living in the places where slugs live. Wet leaves, damp rocks and logs are all excellent beetle habitat. If your yard is naturally dark and damp, don't despair - a yard that grows slugs may also grow their predators as well.
Larger animals such as birds, frogs, and salamanders also love to eat slugs. By feeding birds, creating a bird bath, or simply leaving some bushes full of berries, birds will flock to your garden. While they're there, they'll munch on slugs and snails as well.
Amphibians love the same areas slugs love. If it's not possible to place a garden in a hot spot, take advantage of the dark corners with a small pond or bog garden that sports plenty of hiding places for frogs and salamanders. These animals will also eat your slugs.
Nematodes are available as a form of natural pest control. Watered onto the soil, the nematodes (Phasmarhabditis hermaphrodita) enter slugs' bodies and infect them with bacteria. The nematodes need to be applied onto cool, moist soil, so this control measure is best done in the spring or early fall.
The Anti-Slug Supermarket: Cabbage, Garlic, Mint and Beer
In the pursuit of the slug-free garden, there is a whole range of options. The simplest option is to hand pick the critters off of your plants. Remove enough adult slugs and you'll make a good dent in a population in your garden.
Slugs generally dislike the taste of cabbage, mint, and garlic. Place these plants around others that are more desirable to slugs, and you'll create a barrier for slugs, snails, and vampires, too!
There are a myriad of ideas for slug fences - ways to prevent slugs from crossing into the garden. From crushed eggshells to copper wire, gardeners have tried just about anything to stop slugs from crossing the garden's edge. Eggs shells are sharp, and copper is poisonous. These methods may or may not work.
Beer traps are a popular way to attract slugs to something other that your plants. Dig a hole and buy to the rim a small container of beer in the garden for the slugs. The sweet beer will attract them to an early death in the depths of beer-soaked bliss.
As with all methods of slug control, the beer method may or may not be successful in your particular garden. If it doesn't work, perhaps try another brand? Seriously, there is a university study on it, with Kingsbury Malt and Michelob being the most effective! Coors and Miller Light were the least effective.
Organic Slug Killers
The beauty of organic gardening is that it won't hurt you, your children, your pets, or local wildlife. Some methods of chemical control can be toxic to other animals and to small children. Metaldehyde slug pellets are traditionally sprinkled around plants. They can be fatal to pets and birds, and act as a neurotoxin if eaten by humans.
If you're looking for a natural slug bait, try iron phosphate instead. This is a compound found naturally in garden soil. Brands include Sluggo and Escar-Go! Eating iron phosphate makes the slugs stop feeding, and they die.
Diatomaceous earth is another natural slug killer (and kills all other soft-bodied pests), as it is made up of razor-sharp crushed seashells. The shells cut into their bodies and causes them to dehydrate. Sprinkle it around the base of your plant stems to act as a barrier. Use it with care, since it can easily dry out your hands. Use a mask as well to avoid breathing it in.
Finally, the tried and true "slug salt" solution: don't do it! Not only is it an unpleasant way for slugs to die, salt is also terrible for garden plants. So skip the salt and the metaldehyde and head for non-toxic and ecology friendly solutions to garden slugs.
By Chris Molnar of Go Organic Gardening.com, a website devoted to natural gardening techniques. Read more articles on organic pest solutions and ways to attract beneficial insects to act as your allied army in your garden.