This is the Boscobel School Garden--out at their school forest. The garden is in a fallow grassland filled with perennial grasses--mainly quackgrass!!! The main difference between where the garden is and where the grass is so lush--is a cardboard smother layer with deep mulch on top of the cardboard.
There is a part of the garden that was tilled like this part was--that other part, did not get cardboard and mulch and by mid-summer it looked like the untilled fallow grassland.
In one application of cardboard--all perennial weeds can be eliminated from the garden!!! And the cardboard is usually free from appliance and furniture stores. Plus it breaks down and feeds the soil life.
Just be sure to over lap your seems 4 to 8 inches.