QuestionsHow to growVegetable GrowingBrussel SproutsBrussel Sprouts 0 Vote Up Vote Down asked 14 years ago For the second year my sprout plants have all bolted grown really large and the young sprouts have all bursted open what could be the cause? 1 Answers 0 Vote Up Vote Down Gerry Daly Staff answered 7 years ago You are probably using too much compost, too rich, too high in nitrogen. Apply some potash in winter or spring and firm the soil before planting.