In community-based teaching environments, instructors often operate as quasi-professionals, encountering challenges due to limited access to formal teacher training. Leveraging Garrison's self-directed learning (SDL) model as a theoretical framework, we employed a mixed-method approach to investigate the motivations, self-management, and self-monitoring of dance teachers in this context. Surveying 92 Argentine tango instructors and conducting 21 interviews, this study provided comprehensive insights into their self-directed professional development (SDPD) process. Our findings indicate that teachers are highly motivated to engage in SDPD for the commitment to student success, desire for mastery, and personal fulfilment. They have a fairly clear goal of the type of teachers they want to be; thus, they primarily rely on their prior teaching experiences and self-reflections as a student, as well as other teachers in the community as resources to self-manage their learning and resolve challenges. However, the absence of formalised professional development for tango teachers makes self-monitoring complex, as there are no standardised metrics to evaluate teaching effectiveness. Instead, teachers are forced to rely on critical self-reflections and indirect assessments based on students' performances. These findings bring insights into the professional growth of under-resourced teachers while also simultaneously extending to the broader impact of lifelong learning across various disciplines.