My sympathy's for your loss.
I have sadly had to deal with this in the past, English legislation is fairly relaxed on the subject. Once the ashes are released by the undertaker into your care you can scatter them where you wish provided you have the land owners permission. In this case the local council as others have suggested will be able to tell you who owns the land you have chosen.
My only other thought is the local Royal British Legion branch, they may also be helpful in identifying a suitable location.