Herbicide to Kill Grass but not Blackberry Bush

Q: We have a couple of rows of thornless blackberries on our farm. Thick grass grows all around the canes. Is there an herbicide that will get rid of grass but would not harm the plants? Sharon O’Neal Grant, Tiger

A: No herbicide will selectively kill the grass. However, you can use a spray shield around the nozzle of a pump-up garden sprayer to apply chemical to the grass and keep it off the blackberries. I use a shield made from a twelve-inch diameter plastic funnel. I insert my nozzle into the narrow end and use tape to hold it in place. I put the large end of the funnel close to the weeds I want to kill and pull the trigger.