Not all snails and slugs are pests, so if they’re not eating your plants, you don’t need to get rid of them in your organic garden.
Slugs and snails are closely related.
The main difference is that snails have a shell, while slugs don’t.
Most molluscs live in the water, but slugs and snails are the two that can live on land as well.
In fact, there’s your most important clue right there for how to get rid of slugs and snails in the garden – they like it wet.
So if they’re a problem in your area, try to locate the garden in the sunniest, driest spot, and don’t overwater or use other gardening practices that keep the soil too moist.
Watering in the morning instead of the evening can sometimes make a big difference when it comes to slug and snail control.
But then ideally, we want the garden to be relatively moist for the health of the plants and the soil food web, so a strategy that can sometimes work for getting rid of snails and slugs is to make sure there’s a very dry area around the perimeter of the garden.
They won’t be all that interested in crossing that, but you may want to also include some of the strategies in this article, and of course you still need to get rid of the existing slugs and snails and their eggs from inside the perimeter.
Of course, if you live in a wet area, you don’t have much of a chance of keeping your garden dry, so you’ll have to go right to these other options.
So, how to get rid of slugs in the garden? And snails too? Here’s the big list…
My Favorite Strategies
Unsurprisingly for my regular readers, my favorite strategies for how to get rid of slugs and snails in the garden center around fixing the root cause of the problem instead of using ingredients that annoy or kill the offenders:
- Water. In case you skipped the intro above, go back and read it – that’s the most important step. In summary: if possible, keep your garden on the dry side.
- Wildlife. There are many animals that eat slugs and snails, so invite them into the garden by providing them with various sources of water, food and habitat. Frogs, toads, snakes, birds, lizards, hedgehogs and ground beetles are examples of slug eaters. If you keep a cover crop of a legume or grass or both, you’ll provide safety for those ground beetles – unfortunately, you’ll provide safety for the snails and slugs too, so it’s a bit of a compromise.
- Pets. If you don’t have enough wildlife around, ducks are the best at getting rid of slugs and snails, and chickens are okay, so they’ll take care of your visitors for you – but each of these birds may eat certain plants, so you need to learn how to manage them properly.
- Perennials. Grow more perennial plants, which often have bigger branches and root systems than annuals so they have the jump on slugs and snails in the spring. That includes fruit trees and shrubs, herbs, perennial greens and others. A few of them still may need protection, but they’ll often be stronger than plants that have just come up from seed.
- Transplants. If you still want to grow annuals such as tomatoes and most vegetables, start your plants inside first (or buy them) and grow them to a few inches tall before planting. That can give them a head start on the predators.
Slugs and snails love organic matter, so:
- Remove the mulch. If you keep a nice, thick mulch of leaves or some other organic material for all of the benefits it brings, you may want to rake that away from the beds in spring to remove the moist habitat that snails and slugs love. Of course, many beneficial insects love it too, and it’s great for smothering weeds and so on, so removing it is a compromise, but if slugs or snails are winning the battle, it may make sense to remove it. Leave it in a pile and bring it back when the rain decreases and the sun increases.
- Compost. Keep it away from the garden. Slugs and snails like compost a lot, too.
- Strategize with the mulch. Rake the mulch into a long row beside the garden, compacting it to give a perfect place for snails and slugs to lay their eggs. Then, on an occasional sunny day, move the row over a couple of feet to expose the eggs to the sun, which will kill them. Here’s how permaculturist Sepp Holzer does it (from his book Sepp Holzer’s Permaculture): Slugs and snails lay their eggs in dark, moist places. If you provide them with an ideal habitat to lay their eggs, you can regulate their population. To do this I make rows of freshly cut grass and leaves in the garden. They should be piled higher and compacted more than mulch, and should be kept as moist as possible, so that they provide the best conditions for egg laying. Slugs and snails will travel great distances to use places like these. On a particularly sunny day I then go into the garden and turn over the rows of grass with a gardening fork. Whole clusters of eggs will have adhered to the rotting grass. If you turn the rows of grass over at midday when it is at its sunniest, the eggs will rapidly be destroyed by the heat of the sun and the UV rays.
- Seaweed. Speaking of mulch, when I lived on the west coast, fresh seaweed worked well to keep slugs away from the garden, partially because of the salt, but also because when it dried out, the roughness was difficult for the slugs to navigate over. I imagine the roughness depends on the type of seaweed.
Things To Spray
The following are products that need to be purchased, but they all generally provide other benefits too:
- Effective Microorganisms (EM). I don’t imagine this will always work, but in one garden I used to maintain, I sprayed effective microorganisms and it dissuaded the slugs from eating. I left a corner of the garden unsprayed and they still ate plants in that corner. I’m not sure if the EM just improved plant health to the point that slugs didn’t find the plants attractive, but it was very cool – I still saw the slugs around, but they didn’t eat as much.
- Nematodes. Many people have heard of spraying nematodes on the soil to control grubs. Turns out there’s another species of nematodes that can control slugs: Phasmarhabditis hermaphrodita. I haven’t seen them available for purchase in North America as of this writing, but maybe some day.
- Yucca. I bought some yucca extract once because I was considering selling it as a compost tea ingredient and spreader/sticker for foliar fertilizing. It turns out that mixing it 50:50 with water deters slugs and snails from eating. Just like with the EM, they’re still there, but they don’t cause near as much destruction.
- Neem oil. Some people have had success using neem oil on plants to deter slugs and snails, but it doesn’t appear to be the most effective option. I’ve seen it work on other slug-like insects such as pear slugs, but those aren’t true slugs.
Things To Put On The Soil
There are many things you can put on the soil. Other than the first one in this list, they have to be refreshed regularly.
- Boards and other hiding spots. As mentioned up above in the mulch section, during the day, slugs and snails hide in damp, dark places at or just below soil level. If you place some wooden boards such as 2×6’s on your soil, the molluscs will hide there. Go out every day, lift the boards, and do whatever you want with the them.
- Minerals. Some people sprinkle specific ingredients such as epsom salts (magnesium and sulfur) or salt, which can help get rid of snails and slugs, but it can also cause soil imbalances, so I would only use these if I knew my soil needed, in this example, magnesium and sulfur or salt.
- Diatomaceous earth (DE). This is the fossilized remains of a type of algae called a diatom. It’s like a rock that’s made into what feels like a powder to us, but actually has microscopic sharp edges that cut the slugs and snails. You sprinkle it on the soil and it kills by dehydrating insects from the outside when it gets on their body, or from the inside when they breathe it in. Unfortunately, it kills many beneficials too, so use this with care. I actually stay away from it for this reason, but some gardeners love it. And be sure to buy a horticultural product that doesn’t have chemicals added – some people even opt for a food grade product, but that can get expensive.
- Wood ash. Wood ash is a source of calcium and potassium for your soil, which is great unless of course your soil already has enough calcium or potassium, in which case you don’t want to add much more of it. But a narrow row of dry wood ash sprinkled around plants or around the perimeter of the garden can deter slugs and snails because it desiccates them (draws water out of them). Of course it does the same thing to plants, so be sure to keep it away from them. It also does the same to other soft-bodied insects, so use it sparingly.
- Sawdust, lime, sand, etc. Like the wood ash above, there are several other inputs that snails and slugs don’t like to crawl across because it draws water out of them. Sepp Holzer uses sawdust mixed with wood ash and/or lime. Again from his book: In smaller gardens the following method is very effective in my experience: take a watering can, cut the spout to half its original length so that it is much wider. Fill the watering can with a mixture of very dry fine sawdust, ideally collected from a carpenter or joiner’s workshop. The sawdust must, of course, come from untreated natural wood and not be varnished or contain any other harmful substances. I take the sawdust from a carpenter’s workshop, because the wood there is completely dry and the sawdust is much finer than you would find in a sawmill. Moreover, sawmills mostly work with fresh wood. I mix the sawdust with one part wood ash to ten parts sawdust, or with quicklime powder (around 1:20). Alternatively, you could use both, the only important thing is that all of the ingredients are bone dry. I fill the watering can with these materials and pour a finger’s width border of the mixture around the outside of the lettuce or vegetable patch. Make sure to free the border area of vegetation first. This border of sawdust mixture should remain as dry as possible. This means that from time to time, especially after is has rained, you will have to replace it. The fine dry sawdust mixture adheres to the foot of a slug or snail the moment it tries to get to the lettuce or vegetable patch. The ash and quicklime extract moisture, which prevents them from getting into the crop. If you sit in the garden in the evening, you will be able to see how the slugs and snails turn around when they reach this barrier and go back the way they came. Successes like these will quickly take the fear out of a slug or snail invasion.
From Your Kitchen
There are several foods commonly listed for how to get rid of slugs and snails. Some work better than others:
- Corn meal or bran. Slugs and snails love corn meal, but unfortunately for them, it also kills them. Put some in a jar and lay the jar on its side so the molluscs can get in. They’ll eat some, leave, and die. This works okay with bran too.
- Egg shells. Some people have success with this, but it often doesn’t work. Besides, do you have enough egg shells to protect your whole garden?
- Coffee. Fresh coffee grounds, used coffee grounds, cold coffee – all of these have worked for some people, but don’t work very well for most people. I haven’t found any controlled studies where it worked particularly well either. Apparently, it’s the caffeine that causes problems for the snails and slugs. Perhaps the concentration is what’s important, i.e. maybe most people weren’t using enough. If you have access to a lot of fresh grounds, and if your soil is low in nitrogen, you can try it – but it’s definitely not the most effective method in this list.
- Other foods. Instead of laying down wooden boards, some people use cabbage leaves, citrus fruit peels or overturned half melons to lure slugs and snails. This makes sense for very small gardens.
These traps work well, but you need to have them fairly regularly throughout the garden, and they need to be replenished often, so they make the most sense in small gardens.
- Beer. This is a common strategy for how to get rid of snails and slugs and it works well. Beer attracts them, so put some into a deep plastic container and bury it in the soil so the top comes up about halfway above the soil (at that height, the slugs will crawl in and die, but many beneficial insects won’t). It’s kind of gross, but it works. Unfortunately, it may still attract some beneficials, too, and you need a trap every 10 square feet or so, so it’s most feasible in a small garden.
- Homemade. It’s the yeast that attracts them in beer, so instead of precious beer, you can use a mixture of 1 tsp flour, 1 tsp brewer’s/instant yeast, 1 tsp sugar or honey and 1 cup warm water. The measurements don’t actually matter too much. Some people put 1 tsp of salt in, too.
- Nettle tea. Are you lucky/unlucky enough to have nettle on your property? Although it stings like crazy when you touch it, I’d love to have a ‘nettle problem’ in my yard. It’s a highly medicinal plant for humans and for the garden. And if you put some nettle in water just like we did with the beer above, slugs and snails will gravitate to it like me to chocolate cake.
- Copper. Copper wire/tape/mesh can work well to keep snails and slugs out of the garden. It’s quite expensive, but compared to a lot of these solutions, it lasts a long time. The copper reacts with the slugs’ mucus and gives them what feels like an electric shock. You can wrap it around tree trunks or around the sides of raised beds. Just be sure to get a wide enough strip to really deter them, which could be 4-6” depending on how big the slugs are where you live, or just use multiple strips side-by-side if all you can find is 2” tape. It’s more affordable to get a copper roll at a hardware store rather than buying a product specifically branded for slugs and snails.
- Sandpaper. It doesn’t give them a shock like the copper, but is difficult for them to climb over.
- Lava rock or gravel. These can be difficult for them to crawl over, too, so you can make a perimeter around the garden of coarse lava rock or gravel. Test in a small area first to make sure it works for your particular trespassers, as this is obviously a more time-consuming, costly option.
- Tilling. Thoroughly rototilling the ground in early spring when it starts to get warm will kill many slugs, snails and their eggs, but it also kills earthworms and other beneficials, along with exposing your organic matter to oxidize more quickly, and other downsides, so while tilling can be occasionally useful, I wouldn’t use it only for slug control.
These work, but you need to be more careful with them:
- Metaldehyde. This is what most slug and snail bait used to be made of. It’s quite poisonous stuff, no longer recommended.
- Iron phosphate. These days, the goto is iron phosphate, which kills slugs and snails, but is not so bad for us. It’s marketed as being very safe, but some dogs have been poisoned, whether by the iron phosphate or the ‘inert ingredients’ I’m not sure, so I would keep it away from pets and children. I wouldn’t sprinkle it all over the whole garden, but I would put some down in strategic places and protect it from rain with a wooden board or something similar. Sluggo is a popular brand that’s now OMRI-Listed. Sluggo Plus contains Spinosad, harmful to many beneficials, so I wouldn’t use it unless you have a specific reason.
- Sodium Ferric EDTA. This is the newer alternative to iron phosphate. Unfortunately, the EDTA is very toxic, perhaps even more so than metaldehyde, so I stay away from this one. An example of this is Safer Brand’s “Dr. T’s Slug & Snail Killer.” I’ve read that some iron phosphate products contain EDTA, so if you use one, be sure to find one that is OMRI-Listed or otherwise certified by an organic agency.
- Ammonia. Mix with 4 parts water (1/4 cup of ammonia per cup of water) or according to Linda in the comments below, 20 parts water is fine (slightly less than 1 Tbsp per cup of water). You can spray this on snails and slugs to kill them directly. It’s caustic stuff, so just a small spray is needed. Don’t get it on yourself.
Did I miss any strategies for how to get rid of slugs and snails? Or do you have any questions? Let me know down below…