QuestionsHow to growVegetable GrowingBulb Onionsbolting onions 0 Vote Up Vote Down Rosaleen Carvill asked 15 years ago Some of the onions planted have bolted . Can you suggest why this should happen. Do I remove them or let them grow on . Are they edible? 1 Answers 0 Vote Up Vote Down Gerry Daly Staff answered 7 years ago Sometimes onions bolt due to the trigger of cold weather in spring. They are generally not used as the stem gets tough and the bulb shrivels.