There are two generals ways of doing phytoremediation, one is with living plants, the other is with large amount of dead organic material, which binds the toxins away from living plant roots. The first method, living plants, may take many years to do the job permanently. But large amounts of dead, broken-down organics can allow a crop to grow the first year.

I wanted to grow a garden in soil that had been used for farm equipment storage. It had been sprayed with herbicide every year for many years. I applied about 12 inches of compost over the entire plot and then cultivated it into the soil. This work very well, allowing for a very nice, healthy plant growth the first year of application. After that, 1-2 inches of compost was required to maintain the remediated condition. Within 2-3 years, no further remediation was required, though I continued to add compost for crop plant fertility.

Phytoremediation can be done both by food and non-food crops. It is better to choose the non-food crops. However, depending on the type of contamination food crops may be taken up without reducing the area of that particular food crop from it's preferred habitat.

Clement Ogunkunle

You are 100% right

Heavy metal accumulation in soil and water is one of major problems caused by inorganic contaminants. Their presence in agricultural soils in high quantities have impacted the food security significantly and, by extension, the human health. Amongst various physico-chemical methods available for remediation of heavy-metals-polluted-sites, phytoremediation approaches have been found to be safe and environment friendly. This review gathered scattered information on heavy metal phytoremediation studies published in both review and research articles. It described the impact of heavy metals on food security and comprehensively discussed the application of different phytoremediation approaches for treatment of heavy metal-polluted soils, the basic principles underlining them, their strengths and weaknesses. Our findings indicated that, while hundreds of hyper-accumulator plants are being reported yearly, only few describe limitations inherent in them, such as low growth rate, low biomass production, and low metal tolerance. Hence, this review also gave a detailed overview of research gaps in phytotechnology and advocates consideration of the 'omics' studies; genomics, proteomics, metabolomics and likes in selecting and enhancing potential plants for phytoremediation. For a sustainable large-scale phytoremediation application, we established a multi-technology repair strategy via the combination of different methods like application of biological composts, plant-growth promoting microorganisms, and phytohormones for stimulation of the plant-growth during phytoremediation. We also gave comprehensive insights to proper disposal of plants used for phytoremediation, this subject is often not well considered/planned while deciding the application of plants for removal of heavy metals from polluted environments.

This is a good piece of information to have overview of adverse effects and negative impact

https://www.sciencedirect.com/science/article/abs/pii/S0045653521030277?via%3Dihub