Cut or mow existing vegetation as close to the ground as possible. This will save you a lot of work after removing the tarp! Leave the plant material in place.

Water the area well if the soil is dry. Moisture encourages seeds and roots to become active before being deprived of light.

Cover the soil completely with a light-blocking material such as a black silage tarp (we recommend!), heavy opaque tarp, or several layers of sturdy cardboard. If you don’t use a heavy-duty silage tarp, make sure not to leave it out for much longer than a couple months because it may start disintegrating. Cardboard can be tricky to make sure the edges are well secured so light can't get underneath.We have also had issues with boxes that have lots of packaging tape peeling off and disintegrating into the soil.

Leave it covered. For many annual weeds, several weeks may be enough; tougher perennial weeds generally require longer—often 6–8 weeks or more.

Remove the cover and inspect the area. Ideally, the vegetation underneath will have decomposed or died back substantially. Something we have thought about, but not tried, is to add compost tea, worms, or Bokoshi to accelerate decomposition…

Plant with minimal soil disturbance. Avoid deep digging or tilling, which can bring new weed seeds to the surface. This is going to be depending on your soil and the existing seed bank. Where we have experimented will a small handheld tiller, there was not much difference in weed regrowth, but also not much difference in desired seed growth (so you could save yourself the effort!)

For a vegetable garden, you can occultate beds after one crop is finished and before the next crop is planted. This allows you to suppress weeds while the bed is resting, without herbicides or extensive cultivation.