Pull up any weeds in the area where you want to plant your garden. Pull them up by the roots. Do not cut the weeds, as this will just make them grow faster and will not eliminate them from your garden plot.
Rototill your garden plot to turn the soil and dig up any roots that may still be there. Remove any of the roots or runners that you may turn over in the soil to keep them from taking root and growing again. Rototill both horizontally and vertically in your garden to dig up as many of the roots as you can.
Spray some weed killer on your garden plot the year before you want to plant anything to help reduce the reproduction of weeds. Read the directions on the bottle of weed killer carefully before you buy it, as some chemicals are so potent that you should not plant food in that soil for more than a year. Use an all-natural product for best results in a vegetable garden.
Spread a 2-inch-thick layer of mulch over your entire garden plot to help prevent weed growth. Add nutrients to your soil by using dead leaves for mulch if you are preparing your garden plot in the fall for spring planting.
Cover the garden plot area with thick, black plastic to keep any new weed seeds from getting into your garden plot. Use rocks or some other heavy objects to hold the plastic down.
Till the soil again before planting in the spring to turn any mulch that has not completely broken down into the soil. Plant your seeds. Mulch around the plants as soon as you see the seedling emerging to keep weeds from growing around your plants.
Place pieces of cardboard along the pathways of your garden to prevent weeds from growing there and also to retain some of the moisture from rain and watering.