One of the questions in this thread was to try and ascertain what had caused the population explosion. Many suggestions were given to me. Observing and mulling my experiments I was struck by the conclusions of Bruce on the organic Red Gardens vegetable growing project and Charles Dowding, organic veg farmer). They both are concerned with running trials and collecting data on their experiments. They both focused on removing food sources and shelter for slugs. Dowding is convinced that wooden planters or raised beds just provide the perfect condition for slugs to hide, warm, out of view, protected and feeding on decaying wood.
I started my gardens ten years ago with a view to creating a wildife-orientated garden, at least as part of the vision. Following the experiments above, I decided to try treating the garden more like a vegetable gardener might, in the way of Charles and Bruce. So, rather radically (for me) I took some key steps
4- using slug nematodes in compost bins to reduce egg numbers
5- removing the dozens of log piles. The underside of each log was coated with slugs
In many ways this was just an experiment to see if I could make a substantial change to the slug populations. I wanted to understand the forces at work.
Clearly, each person's garden is different and the variables at play are different, so what works for one person's situation might not work for another; methods that prove effective are not necessarily transferable.
So what happened when I used the "vegetable gardener" clearing up approach in 2021 and 2022? Well, now, in 2023, it's as if I have an entirely different garden - with hugely reduced slug numbers. This year I actually direct sowed plants like ammi and wild carrot and they nearly all matured. I was gob-smacked. I grew dahlias in the front raised bed, where before a calendula would not make it through the night. The change is startling. I can put in a plant, confident that it will still be there tomorrow.
None of the change had anything to do with beer traps, nematodes, barriers or night hunts. Of the five methods I list above, which had the most effect? I think - not using wood chip and removing the wood piles; That is to say - removing rotting wood. I think the slug populations exploded when I added them in and slumped with I removed them.
It is, of course, too soon to draw hard and fast conclusions. We will have to see what future years bring. This year might be a fluke.
Am I suggesting anyone removes wood piles? Not at all. They are wonderful places for all sorts of wildlife - worms, toads, frogs, hedgehogs, beetles etc. I'm just feeding back on my experiment. Bruce and Charles are very passionate about wildlife and growing with wide biodiversity in mind. In their gardens they have areas, away from the veg, where wildlife is given free rein. Where it comes to getting high value plants to grow where they want them to grow, they change tack.
People often comment "ah, but the slug populations will always balance out". I don't think this is remotely true (as discussed up thread. I have lots of frogs); not in a small garden and not with that amount of decomposing plant material to eat. In many situations slugs do not "balance out" any more than rats or deer.
---
I want to thank everyone who commented on this thread - offering constructive ideas. It has all been so useful. I think I have managed to better understand a situation that was genuinely mystifying to me. So, thank you for your thoughts.
the only answer is to grow things that slugs don't want to eat.
Well, for me, this is clearly not the case. I now have a garden full of things that slugs love to eat (see pictures), I just have many less slugs (see today's posts).
That's great . What really interests me is the slugs sense of smell. A few years ago there was some fox sick on my lawn. It was covered in slugs of all description several slugs deep. It was like slug Mecca. They were travelling from all points of the compass. Some of the faithful were spotted yards away heading in the direction of the vomit. Worthy of a you tube video. No snails, though.
Dowding is convinced that wooden planters or raised beds just provide the perfect condition for slugs to hide, warm, out of view, protected and feeding on decaying wood.
I feel there is something in this. During the summer, I collect slugs and snails and deposit them over the road on rough land that won't bother anyone (no, they don't just make a beeline back to my garden, I watched them). During this, I noticed that I have more slugs in very specific places, and those are the places they have good daytime hiding spots. By concentrating on those places, I felt the damage to plants was reduced. It's not a scientific study, or even semi, just a gut feeling.
I'm mulling over the idea of leaving some hiding places next year, some bits of wood or slate, so that I'll be able to lift them during the day and remove the slugs. Has anyone tried this?
Gosh @Fire that's an insane amount of slugs (just read the whole thread which I hadn't seen before)! Must have been very disheartening but you do seem to have found a way to reduce them to a more 'normal' number. I have plenty, and I have a few plants that are never allowed to get beyond ground level, but I've never seen scenes such as those in your photos.
'If you have a garden and a library, you have everything you need.'
Been a very bad yr for slugs here, due to the mild winter and wet summer, no doubt.
I have had some success with egg shells combined with copper mesh for potted plants. I put the pot on an outsized saucer filled with crushed egg shells and then wind copper mesh round the rim of the pot. It's not perfect. One or two do get in. And it wouldn't work for trailing plants. And it doesn't look great. But ... I don't like to just stand by and watch the plants get nibbled to a stalk.
I have tried beer traps in the past, but with no success.
I'm mulling over the idea of leaving some hiding places next year, some bits of wood or slate, so that I'll be able to lift them during the day and remove the slugs. Has anyone tried this?
All the more so because I basically created the problem myself, I think, by adding all the wood chip and log piles. I've said elsewhere recently that if I were to go back ten years and start again I might just go for solely a wildlife garden with no ornamentals. But even then, with that degree of slug-burden nothing much gets a chance to grow. Before I didn't really have a problem with 'weeds'; now I realise that this was because the slugs were eating them all.
The upside is how radically and fast the situation can change - as gardeners know: one year snail explosion, next year few snails.
It feels very odd to be collecting fallen leaves, but I do notice that, as with the logs, the damp leaves at this time of year are coated with slugs. So, collecting garden litter does make a difference.
I put the pot on an outsized saucer filled with crushed egg shells and then wind copper mesh round the rim of the pot. It's not perfect. One or two do get in.
Another mini trial I ran this summer was to try "slug collars". I had around ten dahlia plants. For about half I used collars and half didn't. The collars were a resounding and clear success, esp for those in pots where it's easier to monitor them.
A few caveats - slugs can easily bridge gaps with their body. You have to always make sure there are no leaves hanging down near the collar that they can bridge onto. Make sure the collar is sunk into the ground well and doesn't come up and out over the season. If using canes or the like for plant support, slugs and snails can crawl up them into the plant, but hardly any did this for me. If plants lean over they can lift the collar out of the ground. The collars are not very pretty. Metal ones are available but are expensive.
Using the collar in this way (below) is clearly useless as the slugs and snails will just crawl straight onto the leaf
The plastic collars might be quite robust, but obviously they would be an expensive solution hard to scale up. I could try it just having a few dahlia plants to test on. If someone had a metre square bed and was wanting to grow salad or similar on a patio, for example, or if you had a prized plant you didn't want to get moshed, this a collar might be the way. A friend with a small patio for the collars great for her hostas, just don't leave the leaves hanging down near the ground.
I am trying various ways to make some out of two litre plastic milk jugs and super glue.
Ah, yes, I forgot about the collars. I have a set and have found them pretty good for very upright plants or to allow hostas to get going and toughen their leaves.
Posts
🌱
I'm mulling over the idea of leaving some hiding places next year, some bits of wood or slate, so that I'll be able to lift them during the day and remove the slugs. Has anyone tried this?
I have had some success with egg shells combined with copper mesh for potted plants. I put the pot on an outsized saucer filled with crushed egg shells and then wind copper mesh round the rim of the pot. It's not perfect. One or two do get in. And it wouldn't work for trailing plants. And it doesn't look great. But ... I don't like to just stand by and watch the plants get nibbled to a stalk.