Botanic gardens and arboreta are a vibrant part of the natural history collections community, serving society in areas such as education, recreation, and research. Unfortunately, at the present time dwindling support and advocacy for collections-based research has placed these institutions in the midst of a collections crisis. In this review, I assess the historical importance of living plant collections in supporting research, examine why their research potential is currently unmet, and provide a series of rationales in support of collections-based research. To avert this crisis several things must occur, the most basic of which is stronger advocacy for living collections and the research derived from them. Traditional views of collections management need to be evaluated under new light and the pool of researchers expanded. Formal, on-site programs are not required for collections to be used for research, as off-site scientists can make great contributions. Toward this end, collaborative links between the garden and research communities ought to be enhanced through the pivotal role played by curators and collections managers. Investment in data-management systems are also required to increase collection value and improve the ability to disseminate information to researchers who require it. If provided the necessary leadership and support, living plant collections have great potential to meet future scientific needs.