Ecological restoration can be prone to unpredictable outcomes, but what leads to this variation? For plant communities, conditions during the first year of restoration may contribute to variation among efforts by influencing germination and seedling survival; this, in turn, may impact the community that develops. We are testing this hypothesis, with a focus on the amount of precipitation received by newly sown prairie plantings, with an experiment that manipulates water for the first nine weeks in spring-sown tallgrass prairie plots, across multiple establishment years. We found large differences among the first two years of this study—e.g. 16.9% of sown species germinated in 2014, versus 45.5% in 2015—even in plots for which precipitation was held constant between the two years. Our results show that inter-annual variation heavily influences initial dynamics of sown prairies, yet precipitation surprisingly may not be the driving force behind this variation.