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.