Cherrington innovation and engineering moves forward. Our Rock Pickers provide one step seedbed preparation for an absolutely perfect seedbed. Screen from 1” to 6 inches deep. Remove stones from Ã‚Â½”, Ã‚Â¾” or 1 inch up to 10” in diameter. The oscillating, sifting screen is powered off the tractor’s PTO. Loading paddles convey the soil and debris onto the screen, the screened soil is immediately returned to the seedbed, while all debris larger than the selected screen-hole size is retained in the hi-lift hopper. Choose the screen-hole sizes best suited to your job. Choose the optional powered roller for pre-tilling the soil. Our design reduces labor and improves seed germination results.