Hi Chris, good question - it's a bit of a leap of faith! I've learned to lay in wait for a good spell of rain, then run down to the plot, throw on the mulch, and lay the black plastic there and then whilst the soil is nice and damp. If you don't tread on the growing areas, the moist organic stuff will get carried down into the soil by the worms over the year, and they will help aerate it. And any crops you plant through will work their roots through it, and if you grow root crops you'll have to dig them up to harvest. But it doesn't feel at all like hard work when you're harvesting ;D