What is the name of the story in which the following happens?
Aliens make contact and humans are awestruck/fearful/excited, but as they get to know the them, the aliens turn out to be annoying and boorish. The aliens flatly declare the hollyhock is the most beautiful flower--no ifs, ands, or buts, and demonstrate their technical prowess by greening the Sahara...with hollyhocks. (Maybe they green the Sahara first--with hollyhocks--and explain why hollyhocks with the declaration of their ultimate beauty.)
In the end, humans make use of the aliens' advanced technology to travel to other planets in order to escape the vapid aliens who have now settled on earth.
I read this story in the 1980s or so, but it may be from much earlier.