To erradicate - flatworms so far, so good.
Dinah
Posts: 294
Hi folks. Two years ago I had an idea for catching flat worms, after I found two in the garden. I stood an empty flower bucket with lots of holes in the bottom inside another flower bucket, also with holes in the bottom. I filled the inner bucket with compost containing red worms. I put a half inch of soil in the outer bucket too, so that there was a small, tight gap between the two buckets. I left the two buckets sitting on the earth where I had found a flat worms. I left them over winter until early spring. I had no idea if it would work, but when I lifted the inner bucket out, I found 6 flat worms sticking to the outer bucket walls.
I can't guarantee that it was entirely because of my flat-worm trap, obviously, but I have been doing extensive digging, re-potting, and removing of rotting leaves in the area this year, and have not found a single flat worm. Maybe I just got lucky and found them in time, but I suggest doing the same thing, maybe with more buckets (or large pots) for someone with an infestation.
It seems an effective way to catch them - but how you then go about killing them once caught, I dread to think, since squashing them was an utterly revolting experience that I am glad I don't have to repeat this year, and hope I will never have to repeat as long as I live. 
Posts
Dinah, are you in the UK? The only flatworms I have ever seen are those found in fresh water ponds and those that get introduced into my tropical fish tank on plants. I know that we do have land flatworms - some as introduced species - but have never seen a land one yet.
Respect pf!!!!!
Yes, they are horrible looking things and I can understand anyone "over-reacting." For those who have never seen one, they look sort of like a slightly brownish-grey, slimy, piece of gelatinous ribbon. If you rolled one up and stuck a cocktail stick it would look a bit like a jellied eel (though obviously flat) but the outer edges have a slight translucency, and they have no decorative, petrol colouring on the skin. A horror film featuring a giant, man eating one would be awesome.
Ladybird4: I am in the North of Ireland in an officially "remote area" of "scientific interest." This means that it's even more important to eradicate them. It's likely they arrived with non-native shrubs and trees planted in the area by way of wind-breaks.
Also, thanks Verdun. I love gardening so much that my house gets quite jealous in summer.
Dinah, that is very interesting. I only asked where you were as I know that these horrors have become common in N. Ireland and Scotland and I dread finding the land versions in my garden. I live in the North West of England.
Yes, you were right about them being up here Ladybird.
I suppose the best thing to do is check inside the pots of things you buy from garden centres as soon as you get them home, and drop hints to your neighbours about this too. This year, I replaced the missing worms with a new colony of red one's, and since I have really noticed them around the vegetable patch. I am sure lack of worms is important for the ecology of an area.
I suspect maybe the weather up here, or more probably the peat bogs and heaths may affect how serious the flat-worm problem gets - but if Pansyface found one in London? What is the soil like in your area?
Gosh yes I agree Dinah. They aerate the soil and turn it over and by pulling grass etc. down into their burrows they help to improve the soil texture and the thought of a predator destroying our earthworm population is quite shocking. The knock on effect of lack of earthworms in the food chain has further impact on other creatures. I am lucky with my soil as it is a nice loam over clay and I will take your advice and check any bought plants for the pests.
I just found this web-page wherein the University of Aberdeen are mapping flatworm distribution. It was posted in June 2015, so they may have an update on their findings by now - I'll see if I can find a current map of their distribution. There is a lovely picture of a flat worm in case anyone really wants to see one
https://www.abdn.ac.uk/news/7769/