Pepper dust works but needs reapplying after rain, garden centres
Lion dung Available form garden centres although i have never used it
Or you can get 'sprinklers' that you plug onto a tap and leave turned on. Stick the sprinkler in the border and when it detects movement, it fires a jet of water at the objetc. Garden centres again, although im not sure of a price... Not that expensive I think

i will try the pepper dust,thanks alot