If slugs are shredding your seedlings overnight, here’s the short version. The methods that genuinely work are biological nematodes, encouraging natural predators, picking slugs off by torchlight, and — only as a last resort — ferric phosphate pellets. The popular barriers most of us were told to use (copper tape, eggshells, grit, wool pellets) were tested by the RHS and made no measurable difference. This guide explains what to do, in the right order, for a typical UK garden.
It’s worth knowing up front: you will never get rid of every slug, and you don’t need to. Slugs are food for hedgehogs, frogs and birds, and most species barely touch living plants. The goal is to protect the few plants slugs love during the damp months — not to wage all-out war.
Why slugs thrive in a UK garden
Britain’s mild, wet climate is close to slug paradise. They feed at night and in wet weather, hide under pots, logs and dense foliage by day, and breed fastest when the soil is warm and damp — which is exactly why June to September is peak slug season. A humid summer evening after rain is when most damage happens.
They do the most harm to soft, young growth: newly planted seedlings, lettuce and other salad leaves, hostas, courgettes, runner beans, dahlias and strawberries. Established, woody or aromatic plants are usually left alone. If you’re starting a vegetable garden this is the single most common reason beginners lose their first crops.
Protect the plants most at risk first
Before reaching for any control, concentrate your effort where it counts. A few simple habits prevent most damage:
- Raise transplants before planting out. Slugs destroy tiny seedlings fastest. Grow plants on until they’re sturdier, then plant out — bigger plants shrug off light nibbling.
- Water in the morning, not the evening. RHS research suggests a drier soil surface at night gives slugs less to glide over. Damp soil at dusk is an open invitation.
- Tidy hiding places near vulnerable plants. Lift old pots, boards and leaf litter from around seedlings so slugs have nowhere cool and damp to shelter by day.
- Use containers and raised beds for the most tempting crops. Slugs still climb, but a pot on a hard surface is far easier to defend than open ground. Our guides to growing vegetables in containers and choosing pots for beginners are a good place to start.
The methods that actually work
1. Nematodes — the most effective slug control for most gardens
If you only do one thing, do this. Nematodes are microscopic worms (the species Phasmarhabditis hermaphrodita) that occur naturally in UK soil. Watered on, they seek out slugs underground and stop them feeding, then kill them within a few days — without harming pets, children, hedgehogs, birds or worms. In the UK they’re sold as a living product, most widely under the name Nemaslug, as a sachet of powder you mix with water.
They are brilliant — but only if you use them correctly, which is where most beginners come unstuck. The rules that matter:
- Soil must be 5°C or warmer. Below that the nematodes aren’t active. In practice that means roughly mid-spring through to autumn in most of the UK.
- Apply in the evening or on a dull day, and water it in. Nematodes are killed by sunlight and dry out easily — the soil needs to be moist before and after applying.
- Keep the soil damp for the next couple of weeks. Dry soil shuts them down; water during dry spells.
- It lasts around six weeks, then you reapply. For continuous protection through summer, plan to treat roughly every six weeks from spring onwards rather than as a one-off.
- It’s a living product. Store the sachet in the fridge and use it before the date on the pack — old or warm nematodes simply won’t work.
One honest limitation: nematodes target slugs, which spend most of their time in or on the soil. They’re far less effective against snails, which rest off the ground. If snails are your main problem, lean harder on the methods below.
2. Encourage natural predators
The cheapest, most sustainable slug control is a garden full of things that eat slugs: hedgehogs, frogs and toads, ground beetles, slow-worms, song thrushes and ducks. Encourage them and the slug population looks after itself over time. Leave a wild corner, add a small pond or a shallow water dish, cut a hedgehog-sized gap in fences, and avoid disturbing log piles. This fits the RHS’s current emphasis on predators, cultural controls and targeted biological control.
3. Go on a torchlight slug patrol
Low-tech but genuinely effective: on a warm, damp evening, head out an hour or two after dusk with a head torch and a tub, and pick slugs off your most vulnerable plants by hand. Do it a few nights running when seedlings are at their most tender and you’ll dramatically cut the local population. Relocate them to a wild area, or dispatch them quickly — whichever you’re comfortable with.
4. Beer traps (useful, with limits)
A shallow container sunk to ground level and part-filled with beer will attract and drown slugs. Beer traps do catch slugs, so they help. But they only draw slugs from a small radius, need topping up and emptying every few days, and can catch ground beetles (which are on your side) — so keep them close to vulnerable plants and check them often.
Popular methods the RHS found don’t work
Here’s where good advice parts company with most slug articles. The RHS put the popular home remedies to the test: in a trial led by entomologist Dr Hayley Jones, 108 lettuces were grown with and without the usual barriers, and the protected plants were eaten just as much as the unprotected ones (RHS slug and snail research). The beginner-practical version: don’t spend your first £20 on copper tape and wool pellets — put it into protecting seedlings and improving habitat instead. The barriers that didn’t earn their place were:
- Copper tape
- Horticultural grit
- Pine bark mulch
- Wool pellets
- Eggshells
The likely reason is that a slug’s thick protective slime lets it glide straight over sharp or scratchy surfaces, and even change its slime to cope. Eggshells may be worse than useless — slugs can eat them, so they can act as an attractant. Coffee grounds and salt are two more to skip: there’s no good evidence coffee grounds reliably deter slugs, and salt damages soil and your plants. The practical takeaway is that these barriers may waste time and money. If you’ve been ringing your pots with copper tape, that’s the effort to redirect.
Slug pellets and the law: what’s banned now
The rules changed and a lot of online advice hasn’t caught up. Metaldehyde slug pellets — the traditional blue pellets — are banned in the UK. The ban took full effect on 1 April 2022: it is now illegal to sell, supply, store or use them, because metaldehyde poses an unacceptable risk to wildlife such as hedgehogs and birds (and to pets). If you have an old tub in the shed, take it to a household hazardous-waste point rather than using it.
The legal chemical option now is ferric phosphate (sometimes labelled iron phosphate) pellets. These are approved for use, including in organic gardening, and are far less harmful to wildlife. That said, the RHS’s position is that slug pellets “even organic ones” can still have negative effects on wildlife. We’d treat ferric phosphate as a last resort for a prized crop — used sparingly, scattered thinly per the pack instructions, not as your first move.
A simple slug-control routine for beginners
Pulling it together into something you can actually follow through the damp season:
- Spring: start encouraging predators (water, shelter, hedgehog gaps) and raise seedlings to a decent size before planting out.
- When soil is reliably above 5°C: apply nematodes, and reapply roughly every six weeks through summer for plants slugs love.
- Through summer: water in the morning, keep hiding places clear of your most vulnerable plants, and do a torchlight patrol after warm, wet evenings.
- If something precious is still being eaten: add beer traps close by, and only then consider a thin scatter of ferric phosphate pellets.
Slugs are at their busiest in the months covered by our seasonal guides to what to plant in June, July and August — worth a read alongside this if you’re sowing now.
What you’ll need and where to buy it (UK)
Kept deliberately short and honest — these are the things the evidence actually supports, not the barriers we’ve just questioned:
- Nematodes (e.g. Nemaslug): the centrepiece for most gardens. Sold by garden centres and online — buy fresh, in season, and store in the fridge until use.
- A head torch: hands-free slug patrols after dark. Any decent rechargeable head torch does the job.
- Ferric phosphate pellets: the only legal pellet, for last-resort use on a prized crop.
- Beer-trap supplies: cheap and DIY — a few sunken tubs and the cheapest beer you can find, or a ready-made trap kit.
- For predators: a simple hedgehog house, a shallow pond or water dish, and a bird feeder all pay off over time.
In the UK you’ll find all of these at garden centres and retailers such as B&Q, Crocus, Wilko and Amazon UK. What we won’t be sending you out to buy: copper tape, wool pellets, grit barriers or eggshells — because the research says they won’t protect your plants.
Frequently asked questions
What is the fastest way to get rid of slugs?
For an immediate dent in numbers, a torchlight slug patrol on a warm, damp evening — picking them off by hand for a few nights running — works fastest. For lasting control, apply nematodes once the soil is above 5°C.
Do slug pellets still work, and are they legal?
Traditional metaldehyde pellets are banned in the UK (since 1 April 2022) and must not be used. Ferric phosphate pellets are legal and effective, but are best kept as a last resort because even these can affect wildlife.
Does copper tape keep slugs away?
In RHS trials it made no measurable difference to plant damage. The same was true of eggshells, grit, bark mulch and wool pellets. Your time and money are better spent on nematodes and encouraging predators.
Are slugs actually bad for the garden?
Mostly no. Only a handful of species damage living plants; the rest help recycle dead material and feed hedgehogs, frogs and birds. The aim is to protect vulnerable plants during the damp months, not to eliminate slugs entirely.
When should I apply nematodes?
From mid-spring once the soil is reliably 5°C or warmer, applied in the evening or on a dull day and watered in. Reapply about every six weeks through summer for continuous protection.
Sources
- RHS — Stop slugs and snails (barrier research / Dr Hayley Jones trial)
- RHS — Slugs (identification and control advice)
- Dr Hayley Jones, RHS Principal Entomologist — RHS feature on slug research and control
- Defra / GOV.UK — outdoor use of metaldehyde to be banned (slug pellet ban)
What to do next
Start tonight: clear hiding places from around your most vulnerable plants, switch to morning watering, and — if the soil is above 5°C — order nematodes to apply this week. Then build slug-friendly predators into the garden for the long term.
For more on protecting the crops slugs love most, read our beginner guides to growing courgettes in containers, growing runner beans and growing strawberries in pots, or get the bigger picture in our guide to starting a vegetable garden.
Found a method that works in your garden — or a slug battle you’re still losing? Tell us in the comments; we read every one and update our guides with what readers find works.
