This book presents an overview of plant physiology and the routes of contaminant uptake as well as the potential benefits and limitations of using soil amendments to enhance phytoextraction. While amendments can offer some benefits for contaminant removal from soil, their influence is often dependent on factors such as site conditions, contaminants present and plant species involved. Implementation of phytoremediation technologies, as with other remediation approaches, remains site-specific and therefore requires an understanding of these factors.