[Bobalu]

Cucumber frames are generally wispy trellis frames used for raising cucumbers.

Being so flimsy and weak I suppose she meant it would be rather oafish behavior to smash such things flat.

IMO a strange and very obscure analogy.

[Pelham]

There’s a 1932 British novel that uses the phrase ‘smash-the-cucumber-frames’ to describe one of the characters.

https://tinyurl.com/jqbm5sk