In strategy research, there is a consensus that strategy making resides on a continuum from planned to emergent where most strategies are made in a mixed way. Different contingency factors have been suggested to explain the factors that influence strategy making. Sustainability research seems to overlook most of this development and assumes instead that sustainability strategies are made in a purely planned way. We contribute to a better understanding of the role of different strategy making modes for sustainability in three ways. First, we point to the bias towards planned strategy formation in sustainability research. Second, we propose a new contingency factor to help explain sustainability strategy making based on the nature of the problem addressed. Third, we discuss strategy making for different types of sustainability problems. We argue that planned strategy making is expected for salient and non-wicked problems while emergent strategy making is likely for non-salient and wicked problems.