Answer: Redwood (Sequoia sempervirens) is not considered hardy past zone 7; the Sierra Redwood (Sequioadendron giganteum) is slightly hardier and is rated into zone 6. As a rule these trees do better in the humid and misty Pacific Northwest where summers are not so hot and winters are very mild. If you are determined to try one, try the latter, but don't be surprised if it fails to establish. In a similar vein, the maple would have the best chance of survival in a sheltered spot away from winter winds, with a soil that is acid, evenly moist and yet well drained but it is really too cold to reasonably expect it to survive. I'm sorry I can't be more encouraging.
Q&A Library Searching Tips