QuestionsHow to growFlowersBorder Perennial FlowersFlower beds 0 Vote Up Vote Down Alan Cullinan asked 15 years ago Create flower bed in lawn. Should I use Roundup or just dig over ? 1 Answers 0 Vote Up Vote Down Gerry Daly Staff answered 7 years ago If there are perennial weeds such as dandelions, use Roundup. Otherwise just dig it over turning down the sod.