Evil Leylandii

[garjobo79]

So,these Leyland are nasty burgers aren't they,but also great. Conflicting I know. Must be their roots killed off a large long long established tree. That's ok. I have some planted to form a barrier, a hedge anyway and fast growers. I am concerned though the...roots..might now hit my existing hedge which is laural should I be worried? Thinking come warmer days I..cement..in soil a little barrier..stop it root killing off others. That how it works? Or is it the tree itself, the branches? Those in the know please share your thoughts. Thank you .