Over the past 5 years, we have seen multiple successes in the development of knowledge graphs for supporting science in domains ranging from drug discovery to social science. However, in order to really improve scientific productivity, we need to expand and deepen our knowledge graphs. To do so, I believe we need to address two critical challenges: 1) dealing with low resource domains; and 2) improving quality. In this talk, I describe these challenges in detail and discuss some efforts to overcome them through the application of techniques such as unsupervised learning; the use of non-experts in expert domains, and the integration of action-oriented knowledge (i.e. experiments) into knowledge graphs.