I mulch. I still get insane amounts of weeds and they are usually far more aggressive and larger than the crop I'm trying to grow. I think it depends on the quality of your soil and weeds in the area (existing, from neighbours, etc).
Interesting. Are the weeds penetrating through a barrier like cardboard - or just through a mulch layer? I've worked on some larger-scale permaculture projects where a cardboard/mulch combo managed to kill off a thick blanket of ivy, and that stuff is tenacious.
Through a layer of lucerne. Mixture of inheriting poor soil quality, seeds drifting in and passages where it's been let go (while overseas, etc) and weeds have developed seed heads.
Thistles are a real pain here (South Australia), as are soursobs (oxalis). I have an entire catalogue of weeds.
I agree. As soon as I read the first comment about weeding being unnecessary, I realized that person wasn't dealing with thistles. I am in an ongoing war with those things. Even after covering up a section of garden for two years with opaque plastic sheet and heavy junk, a week after removing it, up they come.
My soil is very good quality, having been improved with chicken & horse manure and composted chicken litter. The problem is I live on a windy hilltop and seeds from all over land where I'm planting. I've even had a wheat stalk show up.
One key to solarisation is to not turn over the soil after cooking the top layer. If you turn the soil, you bring dormant seeds to the surface where they can once again ruin your life.
If you did that properly and still got thistles, then we're doomed!
One thing to try might be two layers of clear plastic with air trapped between - maybe 15-20cm gap. That further raises the temperature of the soil underneath. It's a method used in greenhouses too.
