Brambles are pretty difficult to get rid of because they scratch, and the leaves are almost impermeable! Their branches grow to 3 or 4 metres in length, and when they touch the ground, root themselves in order to grow new shoots.
To get rid of a bramble bush you must first cut away the branches with the aid of a strimmer or secateurs. Once you have completed this task, wait for young leaves to grow back, as these are susceptible to weedkiller. You can then use a weedkiller for difficult weeds, or one for weeds with deep roots, on the young leaves, in order to get rid of the brambles right down to the roots. For a more effective strategy, apply the weedkiller in the autumn when the sap is falling, to ensure that the weedkiller is conveyed right to the roots. In the spring (when the sap rises again and the brambles are destroyed) take a rake and remove the brambles for burning.