I had to look up what slaters were. Different name in the states! Anyhow I’ve had this problem before with entire plantings of young plants, mostly beet, were completely devoured and I found it was that I had a rather thick mulch layer around the plantings and they were prolific under the mulch as they should be. I’m not certain it’s a plant metabolism problem, since if the plants were as young as you say they’re not really equipped to be metabolizing like a more mature plant, as they are still relying on energy from the seed at cotelydon/first true leaf stage. Anyhow I fixed the problem by removing the mulch around the plantings until the plants were more well established. This was in a garden, mind you, but it’s not unheard of for them to eat very young plants, and if you’re in a drought they might have seen it as a food source. I live in the desert and they just target young plants as a matter of course, especially in dry periods.

edit: Looking back on your post it seems to me that there’s possibly an excessive boom because of a lack of predation. Did your planting disrupt the soil enough to disturb centipedes, spiders etc? I’ve noticed over the last few years doing much the same work on more or less poisoned depleted land is that homeostasis of beneficials takes time, and seeing a boom in one species is just a bit of a hiccup in the wax/wane of various species. It’s tough trying to mimic nature. Don’t be disheartened!

• This reply was modified 1 year ago by  Christopher Whitehorn.