How to stop slugs eating plants in your garden in 3 steps
written by Dr Laurence Greenhalgh – Founder of stop slugs – last updated January 2025
In this blog post, we’ll guide you through our three-step process to create a slug-free garden, including an overview of the best slug barriers available. This post is the culmination of years of research and testing, making it the ultimate online resource for stopping slugs in your garden.
Table of contents
Step One- Controlling the Enviroment
Step Two – The Best Slug and Snail Barriers and Repellents
Slug and snail barriers and repellents for potted plants
Slug and snail barriers and repellents for plants grown directly in the ground
Slug and snail barriers and repellents for plants in pots in sheltered locations
Step one - controlling the enviroment
Keep your Garden tidy and create breaks.
This makes it harder for slugs to hide and reduces their chances of feeding on your plants. It also increases opportunities for predators or yourself to find them if you do nightly slug patrols. Additionally, hiding spots provide slugs with places to lay eggs, helping their numbers grow.
Creating gaps between growing spaces, filled with gravel or sand—materials that don’t hold moisture and can’t be hidden in—makes it more difficult for slugs and snails to move undetected from one area to another, further limiting their access to your plants.
Grow as much in containers as possible
Plants grown in conatiners are easier to protect from slugs and snails as there are better barriers available (more on that later) and you can place them away from areas badly effected by slugs and snails.
Let seedlings grow as much as possible before planting them out.
Seedlings are much more vunerable to slug and snail attacks when they’re smaller with less leaves, so make sure to plant them out when they’re bigger they’re less likely to be killed by an attack.
Rake the ground
Consider replacing plants that slugs and snails are eating with slug resistant plants
Slugs and snails don’t eat all plants, so consider replacing those being damaged that you’re not fond of with resistant options like lavender, foxglove, or rosemary.
Water your plants in the morning
Watering your plants in the morning is an effective way to control slugs. By doing so, the soil has time to dry out by evening, when slugs are most active. Slugs thrive in cool, moist conditions, particularly at night. Watering early reduces the damp environment they prefer, making your garden less appealing to them. This simple change in timing can help deter slug activity and protect your garden plants.
Encourage predators
Encouraging natural predators of slugs, such as birds, frogs, and beetles, can significantly reduce slug populations. To attract these helpful creatures, provide a variety of nearby habitats, like small ponds, log piles, and dense plant cover. These areas offer shelter and food sources for predators, helping them thrive and keep slug numbers in check, including reducing slug eggs before they hatch.
Search for slugs late at night / early in the morning
Search for slugs at night using a headtorch. Wear gloves or use slug tongs to capture them, then relocate them far away from your affected plants.
Use a humane baited trap.
Use a bait like beer or yeast mixed with water to attract slugs, but only put a small amount of it in the trap with some gravel, so that they can’t get to the beer and drown. This, paired with a trap designed to prevent them from escaping, such as a Slugvault slug trap. This method ensures the slugs and snails are captured without harm, allowing you to release them far away from your plants.
Use a non baited trap
For example, lay a flat piece of wood in a shaded area near the plants affected by slugs and snails. Overnight, the slugs and snails will take shelter there, and in the morning, you can easily collect and remove them.
Sacrifical plants, slug repellent plants and feeding plants to distract them.
I don’t recommend any of the above for the following reasons. Feeding slugs with cucumber or other suggested foods, or deliberately planting what they like to eat, will inevitably increase their population. You’ll then have to either keep feeding them indefinitely or watch them move onto the plants you were trying to protect. It’s a short-sighted plan.
As for slug-repellent plants, there’s no evidence that any plants actively deter slugs and snails.
Step Two - slug barriers and repellents
Using a Barrier is often a long term soution to protecting your plants and It’s important to choose the most appropriate barrier for your situation. In some cases, you may need to combine two barriers for satisfactory results. I divide choosing a barrier in to the following 3 sections.
1.Barriers for plants grown directly in the ground
3. Barriers for plants grown in containers in sheltered areas
Protecting plants that are grown in pots, planters or any other container are easier to protect, so you could consider moving you’re more vunerable plants into them.
Methodology used to rank slug and snail barriers and repellents
I will score each of the products out of 30 and i will give the score for immpasibility a 3x weighting to account for half of the total score.
very poor = 1, poor = 2, fair = 3, good = 4, excellent = 5
The primary factor for a barrier is that it should be difficult for slugs to cross, ideally it will be impassible, that’s why it has stronger influence on the total score.
Secondary factors include:
- Environmental impact: The barrier should be safe for animals, the earth, and your plants, preferably organic and not break or need replacing after a short period.
- Cost-Effectiveness: While it doesn’t have to be the cheapest option, it should offer good value over a medium / long term by lasting longer and requiring fewer replacements, whilst at the same time achieving your goal of preventing slug and snail crossings.
- Low Maintenance: The barrier should be easy to set up and require minimal effort to maintain, without frequent reapplication or topping up that consumes your time.
By considering these factors, you can choose a barrier that is both practical and effective for your garden.
Barriers for plants planted in pots / containers
The most effective barrier for plants grown in containers (such as grow bags, pots, buckets, or planters) is a slugstand filled with saltwater. This is effectively immpassable and scores well on the other features also.
slugstand
More in depth post: here
Overall Rating: 27 – Excellent
Impassability:
Rating: Excellent – 15
When used as instructed, this barrier is highly effective against slugs and snails. Saltwater acts as a powerful deterrent, causing them to recoil instantly. Unlike barriers placed on soil, it cannot be burrowed under, making it one of the most impassable options available.
Environmental Impact:
Rating: Good – 4
Positives: The product is well-designed, recyclable, and highly durable. It does not negatively impact soil or wildlife.
Negatives: If used incorrectly salt could overflow, nearby plants could be affected. While made of plastic, a metal alternative would offer even greater longevity.
Cost-Effectiveness:
Rating: Good – 4
Although there is an upfront cost, the barrier pays for itself over time by preventing plant loss. By protecting crops and ornamental plants, it provides a long-term, economical solution.
Maintenance Required:
Rating: Good – 4
The barrier requires occasional refilling with water or salt. During summer, more frequent top-ups may be needed, but it can still function effectively using salt alone in cases where evaporation is a concern.
Hanging basket
Overall Rating: 24 – Good
Impassability:
Rating: fair – 9
Make the wire suspending the basket out of copper to slightly improve its slug-proof credentials. Obviously the higher your hanging basket is away from slug habitat the better.
Environmental impact:
Rating: excellent 5
Cost-Effectiveness:
Rating: good 4
Maintenance Required:
Rating: excellent 5
There is none
Coffee grounds
More in depth post: here
Overall Rating: 18 – Fair
Impassability:
Rating: Poor – 6
It has an effect but is easily crossed. Its effectiveness drops significantly over time, especially with rain.
Environmental impact:
Rating: Excellent – 5
It decomposes in situ, releasing nutrients to your soil, and it’s usually making use of a waste product. It can increase soil acidity, so be cautious about that.
Cost-Effectiveness:
Rating: Excellent -5
It’s almost always a byproduct that’s going to be composted anyway, making it a low-cost solution.
Maintenance Required:
Rating: Poor – 2
It will need constant replacing.
Wool pellets
More in depth post: here
Impassability:
Rating: Fair – 9
Definitely better than copper and coffee granules, but not as effective as a slugstand.
Environmental impact:
Rating: good – 4
It decomposes in situ, releasing nutrients to your soil and causing no harm to nature. The only downside is that it’s usually sold in plastic packaging and requires repeat orders as effectiveness drops significantly over a short time period.
Cost-Effectiveness:
Rating: Poor – 2
It requires many repeat purchases and whilst it’s not expensive over a short time frame, becomes poor value for money over time.
Maintenance Required:
Rating: fair – 3
You’ll need to check for decompositing to the pellets often and keep an eye out for slug damage and replace regularly.
copper tape
More in depth post: here
Impassability:
Rating: Poor – 6
It definitely has some repellent effect, and slugs and snails can be seen avoiding it. However, there are many examples of slugs and snails crossing it without issue.
Environmental impact:
Rating: fair – 3
It’s non-toxic to wildlife and your soil, and it’s recyclable and It doesn’t have any significant durability issues. However you’re buying a product which isn’t fit for purpose.
Cost-Effectiveness:
Rating: Poor – 2
It’s a cheap product in tape form, which can be taped on raised beds, or more expensive for rings that protect individual plants. But considering its effectiveness as a barrier is poor, it represents poor value for money.
Maintenance Required:
Rating: Excellent – 5
There’s minimal maintenance, just checking for damage to the barrier and plants occasionally.
Tall planter
Overall Rating: 11- 14 Poor/ Fair
Impassability:
Rating: very poor – 3
Slugs may find it more difficult to reach the plants, but it’s not a foolproof solution and won’t stop slugs from looking, if they can be found high up in blocks of flats on balcony gardens, they can climb up large pot.
Environmental impact:
Rating: Poor/ excellent 2-5
depending on the material
Cost-Effectiveness:
Rating: very poor – 1
Especially as you were maybe going to buy one anyway, but i wouldn’t buy one just to repell slugs.
Maintenance Required:
Rating: Excellent – 5
There’s minimal maintenance.
barriers for plants planted directly in the ground
This is the hardest situation to protect your plants and unfortunatley the most common way of growing them, but there are good barriers available and we’re working on improving them.
The most effective barrier is an overhanging barrier or water barrier. These come in many forms, including a slug fence (which functions like a raised bed and can protect multiple plants, as shown below), a slug collar (which surrounds individual plants) and a slugstand (which can surround individual plants, but not it’s main function). For added effectiveness, these barriers can even be used together.
Extensive experiments have shown that an overhanging barrier or water barrier outperforms wool pellets, coffee grounds, and copper in terms of impassability, low maintenance, durability, and often cost-effectiveness and environmental friendliness.
overhanging barriers: (I.E Slug fence/collar)
Overall Rating: 24/27 good/excellent
Impassability:
Rating: Good – 12
Most slugs and snails find it very difficult to cross, and if the earth is compact, very few will dig beneath them. It’s always a good idea to inspect for slug damage, and if any is seen, try and find the culprit before the area gets infested.
Environmental impact:
Rating: Fair – Excellent – 3/5
The environmental impact depends on the material used, but it certainly scores high for being non-toxic to wildlife and beneficial for your soil. Metal versions are highly durable, while very cheap plastic versions (not recommended for windy areas) have lower durability.
Cost-Effectiveness:
Rating: Good – Excellent 4/5
The cost depends on the quality. Metal slug fences or collars can represent the largest upfront investment in slug control products. However, taking a long-term perspective reveals their value. They help protect your plants—preserving their worth—while eliminating the need for frequent replacements due to their durability. Additionally, they reduce your reliance on repeat purchases of other slug control methods, such as pellets or nematodes, making them a cost-effective solution over time.
Maintenance Required:
Rating: Excellent – 5
There’s basically no maintenance required except keeping an eye out for slug damage and dealing with slugs and snails that manage to pass the barrier. Make sure there’s no tall vegetation or debris nearby that can act as a bridge for crossing the barrier.
slugstand - with just water
More in depth post: here
Overall Rating: 27 excellent
Impassability:
Rating: excellent – 15
It’s very unlikely a slug or snail will cross the water barrier even with no salt, due to it’s steep sides and depth, it’s risky to go underwater and given a choice slugs and snails will find an easier meal nearly always.
Environmental impact:
Rating: Good – 4
positives: It’s recyclable, durable and well-designed. And doesn’t cause any issues to soil or wildlife. negatives: It’s made from plastic product and of course metal would be longer lasting.
Rating: Good – 4
When used to protect individual plants, it will take a longer to recoup the initial investment. The cost is similar to a metal slug collar.
Low Maintenance:
Rating: Good – 4
It will need occasional water top-ups, and occasional overflow is recommended to prevent mosquitoes.
copper
More in depth post: here
Impassability:
Rating: Poor – 6
It certainly has some repellent properties, as slugs and snails are often seen avoiding it. However, there are also plenty of instances where they cross it without any trouble.
Environmental impact:
Rating: fair – 3
It’s non-toxic to wildlife and soil, fully recyclable, and generally durable. However, it’s a product that ultimately doesn’t serve its intended purpose.
Cost-Effectiveness:
Rating: very Poor – 1
Copper ring form is more expensive then tape and considering its effectiveness as a barrier is poor, it represents very poor value for money.
Maintenance Required:
Rating: Excellent – 5
Maintenance is minimal—just occasionally inspecting the barrier and plants for any damage.
wool pellets
More in depth post: here
Overall Rating: 18 – Fair
Impassability:
Rating: Fair – 9
It’s certainly more effective than copper and coffee granules, though it doesn’t match the effectiveness of a Slugstand.
Environmental impact:
Rating: good – 4
It naturally decomposes in place, enriching the soil with nutrients and posing no harm to the environment. The only drawback is that it’s typically sold in plastic packaging and requires frequent reordering due to its short-lived effectiveness.
Cost-Effectiveness:
Rating: Poor – 2
It requires frequent repurchasing and, while affordable in the short term, becomes poor value for money in the long run.
Maintenance Required:
Rating: fair – 3
You’ll need to regularly check for pellet decomposition, monitor for slug damage, and replace them as needed.
coffee grounds
More in depth post: here
Impassability:
Rating: Poor – 6
It does have some effect but is easily crossed, with its effectiveness diminishing significantly over time, especially in rainy conditions.
Environmental impact:
Rating: Excellent – 5
It naturally decomposes in place, enriching the soil with nutrients and often repurposing a waste product. However, it can increase soil acidity, so use with caution.
Cost-Effectiveness:
Rating: Excellent -5
It’s typically a byproduct destined for composting anyway, making it a budget-friendly solution.
Maintenance Required:
Rating: Poor – 2
The coffee grounds must be regularly replaced.
Barriers for plants planted in sheltered containers. i.e greenhouses/balconies
Everything that applies to barriers in unsheltered locations remains the same. However, when there is no risk of rain or strong wind, and the containers are not placed over soil, salt can be used.
salt (thick grain salt like slugsalt is best)
More in depth post: here
Overall Rating: 26 – Excellent
Impassability
Rating: Excellent – 15
As long as it isn’t blown away or washed away by rain, slugs will generally recoil and go in a different direction on touching salt, as it hurts them and can even kill them.
Environmental Impact
Rating: Excellent – 5
Salt is quite long-lasting in sheltered conditions and a natural substance. Even if it does get into the soil, it will eventually be washed away.
Cost-Effectiveness
Rating: Good – 4
It’s cheap and effective. Regular table salt works, but thicker options like rock salt or specially formulated slug salt will last longer. However will need repeat purchases
Maintenance Required
Rating: Poor – 2
Salt barriers need frequent replacing and are easily disturbed, especially around pots. If the area is walked on or exposed to wind, gaps can easily form in the salt barrier, making it vulnerable to slugs.
Common "Barriers" and "repellents" to be avoided
egg shells
More in depth post: here
have no use as a barrier to deter slugs and snails. I wrote a blogpost on this also where i made the conclusion that they can’t stop slugs or snails from eating your garden plants. the sharpness of egg shells i am afriad won’t be protecting your seedlings or lettuce anytime soon from slugs or snails.
garlic raw or as a spray
More in depth post: here
In the video below i used both to try and stop slugs from eating some lettuce i grew in my Garden and it had zero effect as a deterrent, slugs will actually eat Garlic quite happily and garlic spray. So as a form of pest control, Garlic spray has no form for slugs.
step 3 kill slugs
If step 1 and 2 are followed you almost certainly won’t have a slug problem, however if you need a quick fix, you may decide to reduce the slug population in the short term by killing them for example in the spring when you’re plants are very small and extra vunerable. in the UK for example only 9 of the 44 types of slugs actually eat Garden plants and they play a vital role in the ecosystem. However if you wish to kill them these are the most effective ways.
slug hunting
Overall Rating: 21 – Good
Effectiveness:
Rating: Good – 12
Manually picking slugs and snails and killing them, or feeding them to birds, is an effective way to manage high numbers of slugs. It’s also a good opportunity to check if your barriers are still intact and preventing any breaches. It’s best to do this when slugs and snails are most active—consider going out at night armed with a head torch, a bucket, and some slug tongs.
Environmental impact:
Rating: fair – 3
you’re reducing the amount of food for wild animals and slugs and snails are important in decomposition also. A benifit is you you can selectively target slugs that are eating your plants and not innocent ones that have nothing to do with eating your plants. Pet friendly ✔
Cost-Effectiveness:
Rating: Excellent – 5
It’s a free method.
Time Consuming:
Rating: Very Poor – 1
You’ll need to spend tens of hours a week on this method and it’s a short term fix.
nematodes
More in depth post: here
Overall Rating: 20 – Good
Rating: Fair – 9
Adding nematodes to your soil helps control the number of slugs.
Environmental Impact:
Rating: Good – 4
Nematodes are a biological control, making them a more environmentally friendly option. Pet friendly ✔
Cost-Effectiveness:
Rating: Fair – 3
Nematodes aren’t a long-term solution and require repeat purchases.
Time Consuming:
Rating: Good – 4
This method doesn’t take up much of your time.
beer traps
Overall Rating: 22 – Good
Rating: Good – 12
Beer traps can kill a significant number of slugs. Consider using a trap with a one-way valve to prevent slugs from escaping.
Environmental Impact:
Rating: Fair – 3
While you’ll kill slugs that weren’t eating your plants, many baits like beer are natural and break down. However, most traps are made of plastic, although the SlugVault is made from silicone and uses recycled materials. Pet friendly ✔
Cost-Effectiveness:
Rating: Good – 4
Beer traps are cost-effective.
Time Consuming:
Rating: Fair – 3
The traps will need to be emptied and refilled periodically.
slug pellets
More in depth post: here
Overall Rating: 22 – Good
Rating: Good – 12
Slug pellets can kill a lot of slugs effectively.
Environmental Impact:
Rating: Poor – 2
You’ll end up killing slugs that weren’t eating your plants, and the plastic packaging often comes with warning labels, Dangerous to pet owners. And you’re reducing food for wild animals and slugs are important in breaking down organic material.
Cost-Effectiveness:
Rating: fair – 3
Slug pellets are affordable for a short term solution, but if you rely on them they’ll need repeat purchases and add up over the years.
Time Consuming:
Rating: excellent – 5
Once applied, they don’t require much time commitment.
summary
For many people, a quick and effective fix for their slug problem can be as simple as using a physical barrier. A slugstand (for potted plants), a slug fence, or a slug collar (for plants in the ground) can often provide enough protection. Alternatively, spending some time managing the environment appropriately can resolve most slug issues without needing to resort to slug-killing methods. These should never be used just by themselves as like the graph shows above, they're just ineffective.
However, the “holy grail” of slug protection would be a durable, cost-effective, and impassable physical barrier for plants planted directly in the ground. Something like a slug fence that is truly impassable and affordable could be a game-changer. This is exactly what we're working on, send us your email on our homepage, if you'd like to be kept up to date.