QuestionsHow to growVegetable GrowingHerbs, Sagesage spots 0 Vote Up Vote Down john chick asked 14 years ago my sage herb has got brown spots on it. I grow it in a polytunnel next to dill, thyme,oregano. 1 Answers 0 Vote Up Vote Down Gerry Daly Staff answered 7 years ago Sage does not need to be in a polytunnel and may have been scorched by sunshine in the hot weather.