What did Lord Byron mean by "Away with this cant about nature!"?

In Oscar Wilde’s A Sentimental Journey Through Literature, he suggests that the literary critic ‘Mr Noel’ thought Lord Byron was a "true nature worshipper and Pantheist".

Wilde provides evidence to the contrary, saying Byron spoke with contempt of

‘twaddling about trees and babbling o’ green fields’

And that Byron also said:

‘Away with this cant about nature! A good poet can imbue a pack of cards with more poetry than inhabits the forests of America,’

What is meant by these quotes?