Together they mean "Messenger", "herald" and all those other synonyms, so would "Touhou Messenger" or maybe "Touhou Courier" work out?
Where'd you get that one? I'm certainly not finding anything similar anywhere I look.
EDIT: Apparently that's what Google Translate gives you, but since it still gives the pronunciation as just "Hanashi kusa" (literally "talk grass"), I have my doubts. It seems to me like this doujin's title is almost literally the only place on the internet where the phrase is found, so it just might be literal.