The Blog on Slugs & Snails published last year has been the most read of all my Blogs. So I thought we would revisit such a popular subject!!
Protecting your Hostas from slugs & snails, is clearly one of our readers favourite blogs, so I felt it was only right to take another look at it for 2025.
A great deal of last years advice will be the same as this year’s advice, but I have added a few more ideas since then, such as nematodes for slugs, calcium chloride and the use of fabric ground cover. Each of these will be discussed in more detail later on.
You won’t forget about slugs & snails as this is the most popular blog by far. However, I also felt that a reminder was on the cards, so that you can tackle any problems early & upfront. Don’t leave it until the damage can be seen, that’s too late.
Before any new growth on your Hostas, you need to be fully prepared for the onslaught of those wee beasties….the slugs. We need to think ahead slightly and consider what we do about those much talked about molluscs.
The slugs & snails, have overwintered in all those places that you just didn’t have time to tidy up for winter, giving them a lovely, sheltered spot, ready for warming up in the Spring. This particular winter, 2024-25, we have had some spells of really frosty weather which has hopefully reduced the numbers of these critters than survived last year’s milder winter.
Many slugs and snails feed on decomposing organic matter, such as dead leaves, dung, and even dead slugs and snails. They are beneficial animals to have in a garden as they are a valuable part of the composting process. So, not all of them are baddies.
Some species of slugs and snails feed on live plant material and this is why gardeners often consider them an enemy. Many varieties of slugs & snail are actually beneficial to gardeners, breaking down composting material and some even take out other slugs.
The Netted Field Slug, Brown Soil Slug and Common Garden Snail. These are some of the species most likely to be found feeding on live garden plants. These are the ones you don’t want on your Hostas.
So! What should we do about them, and when? What are the alternatives? Which one works best? Let’s have a look! Let’s start with the organic methods of control.
You will always have the edge by having good strong Hosta plants, grown in the right position, without any stress. Keep them healthy and strong. Slugs are far more likely to attack weak & dying foliage, and then onto the good stuff. Keep your Hostas healthy & clean.
Consider natural predators such as the wonderful Hedgehog, Blackbirds, Thrush’s, Robin’s or frogs & toads. Create a good living environment for predators to thrive and they will keep your slug population down. Give plenty of nesting sites for birds, such as Thrushes & Blackbirds. They just love eating slugs. If you have plenty of trees, these can offer nesting for birds, as well as valuable shade from the sun, for your Hostas. Maybe get some ducks!!.. or at least have a bit of water somewhere, like a wildlife pond.
Natural predators will also include humans. See yourself in the garden, every night, with a torch on your head, picking off the slugs one by one? Commendable for those that do, but I have better things to do, such as my valuable sleep.
Slug feeding happens at night, so often the holes and slime trails left behind will be the only clues as to who has been nibbling.
Slugs don’t like surfaces that are difficult to navigate. Try strategically using pine bark or gravel. They just don’t like these surfaces, and tend to look for something else to eat, that doesn’t mean crossing that gravel path. But they will anyway.
Take away their natural hiding places. Clear up those bricks and broken slabs. Make it difficult for them. Keep all areas clean of other debris such as leaves and twigs but be careful of disturbing any overwintering Hedgehogs.
These efforts may well help reduce the problem of slugs but may not entirely eliminate them. The great news is all of the above are FREE! This is a good start.
There are hundreds of ‘proprietary’ controls on the market. I will say now, that some of these will work for some people, but not all of them work for all the people all the time. Of course, these all, cost money.
Let’s have a look anyway. Firstly, we will tackle what you can do with planted Hostas.....
Coffee grounds…. can often be free from a local coffee outlet. Coffee grounds contain a naturally occurring fertiliser, poisonous to slugs.
Wool Pellets …. Make it difficult for slugs to navigate. These are relatively effective but they’re not cheap. More likely to be used with containerised Hostas.
Slug traps.... will collect many slugs, but you will have to remove them from the trap each morning. Many use beer in the trap but try citrus peel. Any slug trail that you get on your hands, try vinegar, to clean them.
Plant ‘slug repelling plants’.... around your Hostas. These are generally aromatic or strong-smelling plants that confuse the slugs. Anything from the Allium family, strong mint, chives, Garlic, Fennel, or even Foxgloves & Geraniums.
How about this… slugs are lazy, if there is something easier to eat, they will. Try planting a ‘sacrifice’ crop somewhere near your Hostas. Sow some salad stuff for the slugs to eat, instead of the slugs eating your valuable Hosta leaves.
Hostas grown in pots and containers....
Use sharp horticultural grit on the surface of the pots. Maybe crushed eggshells instead (or as well).
Copper band.... placed around the pot. Does it work??? Maybe sometimes. Or get really silly and cover the pots with Vaseline, making it difficult for the slugs to ascend, or spray the pots with WD40. Works for a day or two.
Put some wire or netting in the drainage hole to stop the slugs entering your pot that way.
So you can see that there is a small group of repellents, free or otherwise that might or might not work.
There are a few things you shouldn’t try…
Salt.. do not use salt. This will draw the water out of the slugs and kill it by dehydration. Not a pretty sight and shouldn’t be done. The salt will also damage the plants, maybe even kill them. Epsom salts is an alternative but do not to use table salt at all.
Vinegar.... doesn’t kill slugs at all. The only use for vinegar is to remove snail trail or washing hands if you have been handling slugs.
Slug Pellets…(yes they are still available). As of April 2022 slug pellets containing Metaldehyde can no longer be used and are banned from being sold. About time. There is now only one type of slug pellet approved for use in gardens, those based the active ingredient ferric phosphate. However, as you might expect these are less effective. Available at most garden outlets.
Just a quick word of warning for those who incorporate any form of fabric ground cover control. Yes, it will certainly do its job of keeping down the weeds. However, if you get a chance, take a look underneath for slugs & snails. It is a near perfect place for them to be protected from the heat of the sun in the summer and overwintering from the frost in the winter.
Nematodes are well known for helping to control vine weevil, but did you know you can now get a nematode slug control. This is not cheap but seems to be effective, particularly with Hostas in containers.
One of the proprietary brands in Nemaslug. It costs around £32/£33. You can buy it on-line. Application will cover about 100 sq mtrs and needs to be re-applied every 6 weeks, using a spray applicator attached to a hose pipe. It will only work at or above 5c.
Nemaslugs are found naturally in the soil and are approved by the Soil Association for use as an organic control. Yes, it is perfectly safe for birds & wildlife, pets and children alike. It’s very easy to apply.
Spraying plants with a protective calcium chloride solution, such as Grazers G2 could be another control. Dedicated use can yield results, as long as you repeat applications after rain. Rain will wash it off. Unlike traditional methods that use harmful chemicals, G2 formula acts as a deterrent, creating a barrier around plants without harming other animals or pollinators. The G2 formula contains natural ingredients that deter slugs and snails while being safe for pets and wildlife.
All is not lost though. There is one completely natural way of controlling slugs on Hostas, and you can make it yourself.
Garlic Spray. Try spraying your Hostas with a home-made recipe of Garlic Spray.
Above is the QR Code for our own recipe. Really easy for you to make your own. Go on. Give it a go.
Just a few guidance rules for applying Garlic Spray.
Don’t spray when it is raining or going to rain. Common sense really, it’ll only wash off.
Equally do not spray in scorching hot weather, it will only help burn the leaves more.
When applying, do both the top and underside of the leaves.
You may need to do this, weekly, or monthly, depending on how effective it has been. This can be seen by the number of slugs and snails that are still apparent.
Slugs detest the smell of garlic and will stay well away from it.
When you make this recipe, usually in a kitchen, open all the doors & windows. It will stink.
What I love about all of these solutions is that a lot of people will try more than one of them, and that’s ok! Find one that works for you and carry on using it.
I have tried virtually all of these methods at some point or other and none of them are perfect. If I had to put them in order of success, then Garlic Spray & Nemaslug would be my first two choices. It has to be said, I haven’t tried Calcium chloride for two reasons. Firstly, it does sound like a bit like a chemical and I want to be as organic as I can keep it, (it is organic though. Just doesn’t sound like it), the other is that you don’t see it very often in the shops, like you do slug pellets.You can buy it on-line easily enough.
Hostas are beautiful plants, and the challenge of keeping slugs & snails from your Hostas, is really worth it. You don’t need me to tell you that.
They tend to be able to handle whatever nature seems to throw at them. Every year they come back up and carry on regardless. I just love them!
You may be surprised at the are large number of Hosta varieties that are slug resistant. Varieties with thick ribbed leaves, blue leaves or those with a waxy layer are far more resistant to attack. Try growing these and see if there is a difference. Slug resistant varieties mean just that… resistant. It doesn’t mean they won’t get bothered by slugs, but they are more tolerant, and less likely to.
I often hear that people don’t have Hostas in their garden because they are always ravaged by slug & snails. For those in that frame of mind… think again! They are not that bad, and with just a little care, they can be fantastic.
Take a look at the dedicated section of our website featuring the resistant varieties. https://www.rewelahostas.com/slug-resistant.
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John Plant
Rewela Hostas
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