Cardboard is great stuff, no need to use plastic landscaping fabric. I cleared this bed of ivy and I'm layering it with cardboard till I get round to planting it out. Cardboard is surprisingly long lasting but porous and biodegradable- eventually. A layer or two will suppress unwanted growth for months before it disintegrates. I won't be doing any planting here till spring and there will probably still be wet and decaying cardboard on the ground. At which point I'll simply dig through it with the spade.
 This approach can amplified by 'lasagne mulching' for soil improvement. Several years ago I joined in with a group of volunteers to mulch a large area at a community garden. A base layer of cardboard was covered with several inches of well rotted horse manure followed by another layer of cardboard topped off with a several inches of woodchip. Six months later the area was relatively weed free with a good friable topsoil where the various "ingredients" had merged into the ground.