Abstract: When nutrients run out, many bacteria form dormant spores that stop growth but can tolerate harsh environments. This starvation response has often been interpreted as a bet hedging strategy in case conditions improve much later. However, spores also contain a memory of the conditions under which they sporulated. Spores formed in extremely nutrient poor environments may not germinate efficiently, suggesting that generating spores during periods of nutrient richness could actually be a beneficial strategy. One way to achieve this could be to form spores in biofilms, where high cell density can accelerate sporulation through cell-to-cell quorum sensing signals. The soil bacterium Bacillus subtilis is a model organism for both sporulation and biofilm formation, but our understanding of spore formation in biofilms has been hindered by the fact few experiments have used strains proficient in both phenotypes. Using wild strains lacking lab domestication mutations, we find that in biofilm conditions, sporulation can progress rapidly, creating colonies with high spore counts even early in growth. By integrating separate fluorescent reporters for vegetative cells and spores, we find that developing biofilms generate a distinctive pattern: an expanding ring of vegetative cells surrounds a spore-rich core. We compare time-lapse data to predictions of a reaction-diffusion model of biofilm growth to show that nutrient conditions and the timing of cell differentiation networks combine to pattern spores and cells during biofilm development, creating a rich source of spores from nutritious conditions.