Fun fact: in a sense, this sentence translates as 'green green-straw'. Since Welsh was originally a language, like many, which did not distinguish between green and blue (and certain greys), the word 'glas' was used for the portion of the spectrum which English divides between green and blue. Linguists call this unified color 'grue', so alternatively one could translate this 'green grue-grass'. The word 'gwyrdd' was a later loanword from Latin (viridis). which is why grass, which is green, is called glaswellt.
And the grue grass grew all around and around and around
And the grue grass green all around