I want to do a better review than that later but here's the description from Librivox:
Do remember reading a panic-mongering news story a while back about genetically engineered “Frankengrass” “escaping” from the golf course where it had been planted? That news story was foreshadowed decades previously in the form of prophetic fiction wherein a pushy salesman, a cash-strapped scientist, and a clump of crabgrass accidentally merge forces with apocalyptic consequences. A triple-genre combo of science fiction, horror, and satire, Greener Than You Think is a forgotten classic that resonates beautifully with modern times. This is a faithful reading of a 1947 first edition text.
Such a surprise ending.
So very funny! Low key funny but it is there continually and emphasized perfectly by Elliott.
Can't praise this book enough.