Description of the subject. Wildflower strips are used to provide flower resources for insects in agroecosystems. There is a need to determine implementation processes that maximize the development of the sown flowering species. Objectives. To determine the effect of i) sowing period (autumn and spring) and ii) early cutting of annuals during the first growing season on the development of the sown perennial species. Method. We surveyed species development during three years (2012-2014) in 24 plots in an experimental wildflower strip. Plots were sown either in autumn or in spring, and received or not an early cutting management in 2012. Results. Sown species were favored by autumn sowing. A few species did better after spring sowing. Two years later (2014), early cutting management enhanced sown flowering species abundance and diversity in case of spring sowing only. Conclusions. Studying implementation and management protocols is of first importance to improve the efficiency of wildflower strips. We recommend autumn sowing as a first approach, and mowing aimed at controlling annuals in the first year after sowing.