"Broadback"wrote
No matter how I hunt for runner beans, and pick all available, the next
day on walking past I almost bang my head on a large bunch.

Am I blind, or do they really grow that fast?

I expect you are missing them, no matter how hard one tries to pick them all
if someone else walks down the row they will spot ones left behind.
The Foreman's always telling me off for missing them. :-)

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Regards
Bob
in Runnymede, 17miles west of London, UK