QuestionsHow to growFlowersBorder Perennial Flowersbamboo worry 0 Vote Up Vote Down Gerard Kelleher asked 8 years ago I planted bamboo at the end of my back garden 6/7 years ago and am now worried that is seems to be spreading to neighbours sites. if i dug a trench and laid paving slabs on their side would it halt spread or how deep do the roots go. 1 Answers 0 Vote Up Vote Down Gerry Daly Staff answered 6 years ago The only way to stop sreading shoots is to dig them out when first seen, or dig out the whole plant, or kill it in situ with Roundup.