In Netherlands you probably have Neudorff's Ferramol available, and it's worth trying again in my opinion. It's much the same stuff as Sluggo. It works very well against all sort of snails without shell. The ones with shell tend not to spend time enough on the ground to attract them. It does help to pick them. Check dailias daily, the are slug magnets. A piece of honey or canatalupe melon is really (!!!) effective too, if you have time to check now and then and pick them. Iron sulphate and picking really helps, and pretty fast too. Withing a short week I can go from mass invation and picking about 100 a night to hardly find any. This is what I do, and it works very well here. Ferramol has been around for ages and does well in tests. There's the nematodes you water into the ground, some regard these as the most effective in the long run, but you haveI to keep it up for a couple of years. Best of luck with the slugs. It doesn't have to take a long time for you to notice major improvement :-)

For me, containers left on the patio deck generally do not attract slugs/snails. But the containers that are on soil or raised above soil by stands are easily reached by these predators. One idea that I heard of was to put vaseline around the pot for at least 1". The slugs and snails will not pass through this sticky substance. I have used this method and it does work. You just have to apply the vaseline where you will not touch it. It will need reapplying once in a while. And don't forget to consider that the slugs and snails that are on your hosta may already be living in your pot! I remember purchasing a hosta and I kept finding slugs on it. Finally, I removed the hosta from the pot and voila! there they were! Here are other methods to deter snails and slugs for containers. I copied and pasted from the link provided. Here it goes: Gritty substances. The first method for garden snail and slug control is to use a gritty substance. Snails do not travel over gritty substances, such as crushed eggshells or sharp sand, that have been spread around your container plants. Put a layer of grit in your plant containers, and snails will avoid these plants. If they do crawl there, the grit will clog their slime glands and it will kill them. Spread sharp and angular gravel (not smooth rocks) over soil so the snails canâÂÂt climb. All of these gritty substances will irritate the snail and slugâÂÂs delicate undersides. WD-40. To deter snails in your container garden, you can set up barriers around your plants or their containers. For example, you can spray a band of waterproof WD-40 around your containers, and the snails and slugs will be unable to climb up it. WD-40 is waterproof, so it will be effective in the garden even after rain or watering. When spraying the WD-40 around the containers, make sure there are no gaps, as the snails and slugs will climb through any spots youâÂÂve missed. Also protect any plants from the spray by covering them with newspaper or a sheet of plastic. The WD-40 should last an entire season. Copper wire. Another snail barrier is copper wire. Attach copper wire around your plant containers or around a thick plant stem. Because snails have acidic slime, they will get a shock if they touch copper wire. It wonâÂÂt kill them, but it will keep them from climbing up your plant containers or onto your plants, and they will go elsewhere. Hope this helps. Babka, your plants are looking fantastic! Jeffoxtoby, you have provided some good information. In regards to your reference to frogs, I have been told that it is toads that eat a large amount of slugs. Perhaps you can look into that. Here is a link that might be useful: Balcony Container Gardening: 8 Methods for Garden Snail and Slug Control

>"Sending them back to whence they came (the neighbor's overgrown yard)" Yeah. You watched them crawl from over there, did you? Do you really think they don't breed in your yard because you'd rather that they didn't? You should stop weeding, because you kill plants when you do it, and you have no right to. You shouldn't dig to plant, either, because you are certainly severing living creatures in half when you do so. And even walking on the ground outside, you are killing many invertebrates with every trip to the garden. How can you ethically justify all this destruction just because you want something pretty to look at? What is wrong with you, that you don't think that nature is good enough for you? You should stop doing any kind of yard and garden work right now, before you kill more defenseless creatures. Your arrogance astounds me. But if you are intent of continuing your wanton destruction, I think that you should definitely do a catch-and-release program. You should build the traps yourself--I should think that you need at least 30--and you should make sure to check them and release the trapped slugs and snails at least once a day--twice a day if it's sunny. And the location should be at least 5 miles away if in the city--10 miles in the country--in order to make sure they don't return.

I was thinking about this thread as I was doing some reading in various places about humus. Even wikipedia puts it this way about stable humus: " this is organic matter that has been protected from decomposition by microbial or enzyme action because it is hidden (occluded) inside small aggregates of soil particles or tightly attached (sorbed or complexed) to clays. Most humus that is not protected in this way is decomposed within ten years and can be regarded as less stable or more labile." It also refers specifically to lignin being one of the main precursors to humus, and that black carbon (e.g. biochar) also seems to contribute a lot to stability. Interesting the way that OM gets attached to clays. I don't know if this is actionable information or what it tells us exactly about what to do in this case; but I'd be tempted to place an emphasis on woody/pulpy inputs (or composts from them) in adding organic material, or at least plant material (stems? corn cobs/stalks? etc) or paper/cardboards that have fair amounts of lignin and get some charcoal/biochar in there too. Just speculating somewhat, but hopefully logically. This will have implications for nitrogen and other nutrient availability - i.e. it might make growing some types of plants or getting good yields harder, at least in short term - but might have benefits in getting there to more stable soil in long term. FWIW.