As it becomes clearer that we all need to come away from using chemical slug pellets, the question of "what else?" is a fair one. Many of the alternatives can have mixed results, especially when they're not used correctly. Having grown hostas for over 30 years now, we have tried just about everything and we're always looking for more options and new ways to protect our plants, whilst avoiding harm to pets and wildlife. What we do know, is that the harmful metaldehyde pellets are now banned in the UK and have been since 2020 (maybe one of the only good things to come out of that year). Metaldehyde kills slugs and snails, but can then be harmful if those dead slugs and snails are eaten by birds or mammals such as hedgehogs. Metaldehyde can also kill domestic pets such as cats and dogs if ingested.
In this article we want to go through a few of the organic slug protections, what we have found to be their pros/cons and how we recommend to use them most affectively. Please feel free to give your opinion on your favourite organic slug prevention in the comments.
We ran a trial here at the nursery with sheep wool and had some very positive results. Although some holes did appear, it was very minimal so it was shown to give good protection. One of the main downsides we found was that over time as the wool settles it becomes less affective, so reapplying every month or so is recommended. We also found that it was quite popular with birds, who were pulling strands off for their nests, this could be seen as a positive and a negative.
If you would like to get hold of some sheep wool to try it yourself, we have used wool from - woolshred.co.uk
Our main form of slug protection here at the nursery. We have found garlic to be one of the cheapest, easiest and affective ways of keeping our hostas free of holes. Garlic wash is really easy to make at home, you can use our recipe here - Garlic Wash Recipe.
As great as it is, there are downsides to using garlic wash. One of the downsides is how often it needs to be applied; we recommend once a week but this may have to increase if there is rain. For ease we would suggest you make up a sprayer of garlic wash and leave it by you back door to use as much as you can when going out to the garden. The other downside is the smell, although this doesn't linger for very long we would recommend not using garlic wash just before you're about to have a bbq or a day out in the garden.
For those who are less keen on using garlic, we sell an alternative - Slug and Snail Repellent.
Another good organic alternative to slug pellets is coffee grounds, this by-product can actually work really well if used regularly. If you're a big coffee drinker, like we are at the nursery, you will have plenty off discarded coffee grounds to use so this is affectively free.
It is important to know two things before attempting to use coffee as a slug deterrent. One is that coffee grounds alone will rarely be enough to keep you're hostas free of holes, coffee grounds can really help but are best used in conjunction with other preventatives. The second important thing to note is that the coffee must be caffeinated, because it is the caffeine not the texture that the slugs do not like.
Baked Eggshells or Crushed Seashells
We have heard very mixed results from customers on this one. Some people will completely swear by eggshells and some will instantly discount it as an old wives tail. The truth is eggshells can be a good barrier from slugs and snails but shouldn't be relied on as your only means of protection. The eggshells must be baked in order to harden them up and you may need to reapply them in they start to settle into the compost around the plant.
Crushed Seashells are a much better option to baked eggshells as they are already very hard so can be applied without baking. They are also a by-product of the seafood industry.
Probably the one that we should all be aspiring to, try encouraging more wildlife into your garden. Birds, hedgehogs, frogs, toads and slow-worms will all eat slugs and snails. By making your garden a haven for wildlife, you will be rewarded with natural predators to keep your slugs and snails under control. You may consider a bird feeder or nesting box to encourage birds. A wildlife pond is an excellent way to encourage frogs and toads into the garden, this will also make your garden more appealing to hedgehogs and birds. Using organic methods of keeping the slugs and snails off your plants will also help keep this wildlife safe from secondary poisoning.
In summary...our recommendation would be to use at least two of the methods above for the best results. If you have any organic methods that we have not mentioned please leave them in the comments!