Some plants, such as ragweed, mustard, oilseed rape, sunflower, cabbage, and duckweed (for semi-aquatic gardens) are metal hyperaccumulators.

If you have contaminated soil, you can grow these plants in the contaminated soil, then remove the plants and dispose of them safely. This will take several growing seasons to bring toxic metals levels down to acceptable parameters, but it has the advantage of being extremely inexpensive. Urban soils polluted by leaded paints and vehicle exhaust will likely be usable after one or two seasons of phytoremediation, but extremely polluted waste sites could take decades, starting with a narrower range of hyperaccumulator plants that can survive the initial high levels of contamination.

Adding mustard to your regular crop rotation is also useful for pest and weed control.