Self-explanatory to Britishers in the 1990's, this description of unruly
hair will puzzle the rest of us, so:
1. Terry Waite served as the Anglican
Church's international diplomacy negotiator. In 1987, he was himself taken hostage in Lebanon and held mostly in solitary confinement until his release in 1991. He's a
well-known public speaker now.
2. "Allotment" in Britain is an urban rented garden
patch.
Hence, Terry Waite's allotment would be untended and weed-choked.
I haven't determined if Waite actually was an allotment holder at the time of his confinement.