[The Mouth of Sauron]

The Brandybucks planted and tended the Hedge for generations as a bulwark against the Old Forest .

Would it not have been more sensible to construct a wall ?

Another thing . When Frodo, Sam, Merry and Pippin are returning to the Shire , as they approach the Brandywine Bridge and its locked gates there is no reference to the North Gate in to Buckland . Surely Merry could have got through that gate , even although Gandalf says just prior to leaving the Hobbits to see Tom Bombadil that Merry might " have more trouble at the North Gate " than he thinks ?