Dear Hortiman,
Treasure can come in all forms, to include Horticultural items, Evesham is a good place to look, but good treasure will never be left on the surface. Only last year we found an early Simar of 1919 – 1920, complete except for the engine missing. The year before we turned up a 1900’s Greens Silens Messor from 1900 in Malvern.
The best places to look is where the Horticultural belts were in the past but have long since gone, try Hertfordshire which in the 1920’s was known as the sea of glass!
Kind regards
Big Ears