great idea with the crate, I've been just rethinking what a pain in the balls it is to get solo cups out to the woods, without mangling them or spilling dirt everywhere, ugh been there lol.
I've had slug problems in the past myself, in my experience, you would probably see them all over the place in the frame itself, probably dead. I've also noticed they come out if its reallly rainy/humid etc. I've also ONLY had them eat/destroy VERY young seedlings, leaving tiny stems that's all. idk why though. I've also seen weird little beetle things? that live in/on top of the soil if its moist enough and eat tiny seedlings too, they would also probably be right in the cup still though. try diamataceous earth if concerned. the beer can trick will also let you know if slugs are indeed in the area too.
I've had slug problems in the past myself, in my experience, you would probably see them all over the place in the frame itself, probably dead. I've also noticed they come out if its reallly rainy/humid etc. I've also ONLY had them eat/destroy VERY young seedlings, leaving tiny stems that's all. idk why though. I've also seen weird little beetle things? that live in/on top of the soil if its moist enough and eat tiny seedlings too, they would also probably be right in the cup still though. try diamataceous earth if concerned. the beer can trick will also let you know if slugs are indeed in the area too.