RONSTAR brand oxadiazon is a preemergent herbicide that controls a variety of annual broadleaf and annual grass weeds. Offering a conducive environment for sprigging, Ronstar controls weeds through their shoots rather than their roots, so it won't harm turfgrass roots in the process. In fact, Ronstar can be used for long residual pre-emergent weed control even in areas that may need to be sprigged or where turfgrass roots are already weakened due to pest, mechanical or other damage.