When do summer annual weeds germinate?

Summer annual weeds are characterized by their life cycle, which begins with germination in the warmer months. These weeds typically germinate in the spring or summer, taking advantage of the rising temperatures and increased moisture available during this time. Once germinated, they grow quickly, flower, and set seed all within the same growing season, typically dying off when the weather becomes cooler in the fall. This life cycle strategy allows them to thrive in environments where conditions are favorable for their growth specifically during the warmer months.

In contrast, the other options represent different seasonal patterns that do not align with the growth habits of summer annual weeds. Germination in the late summer to early winter, during winter months, or at the beginning of fall pertains to either winter annuals or perennials, which have different adaptive strategies to survive in various climates and conditions.