In Flanders Fields?

No, in Richmond, Surrey.

American YWCA worker Moina Michael was inspired by John McCrae's poem to adopt the poppy as a symbol of remembrance, & in turn, in 1921 Frenchwoman Anna E. Gurein sent sellers of artificial poppies to London.
The Royal British Legion Poppy Factory was established in 1922, & now makes about 36 million remembrance poppies a year. A futher 5 million are made at Lady Haig's Poppy Factory in Edinburgh.
The Richmond factory employs 40 full time workers, & about 90 local home workers. Many of them disabled ex-service people.