Could tending to weeds inform more reciprocal modes of occupying space? Noticing the mutual thriving of unlikely neighbours, this thesis learns from the resilience of undesirable ecologies to investigate how we might better grow together more sustainably. The entanglement of social and environmental needs is addressed by drawing on ruderal ecologies (a term for disturbance-prone plant communities) to develop an interdisciplinary and transcalar approach to architecture. Tools for noticing overlooked worlds are first created to learn specificity through modest site interventions in ruderal places. Like the dandelion rooted in a sidewalk crack, a reflective design project then imagines how unsealing paved grounds would reconfigure relations among human and nonhuman occupants in Ottawa, Canada. To find more hospitable grounds for growing and dying in common, a ruderal approach shows that ecotones of abundance can flourish among the gaps in things that matter, if tended to carefully.