Polymers have been used in agriculture and horticulture since the middle of the last century. There is a tremendous potential for using polymers in agriculture and our fields and garden would look very different if we did not use polymers in them. This review traces the history of polymer use, discusses the markets for polymers in these applications, and describes in detail the different types of polymers that can be used and their specific applications. An additional indexed section containing several hundred abstracts from the Polymer Library gives useful references for further reading.