When I say they won't grow, I'm referring to growing naturally out on the hillsides or wherever. Irrigation is required to grow non-native plants here.

Klamath Falls experiences significant seasonal variation in monthly rainfall. The rainy period of the year lasts for 9.0 months, from September 18 to June 20, with a sliding 31-day rainfall of at least 0.5 inches. ... The least rain falls around August 1, with an average total accumulation of 0.2 inches.

That's way more rain than we get here. The last time water fell from the sky here was months ago.