At a glance: Kerr Applecrab is an applecrab tree rated hardy to zone 2 in our ratings (winters to -50°F), not self-fertile, so it needs a different variety nearby as a pollenizer (bloom group 4 of 7, mid for an apple or crabapple), and it ripens about Sep 11 to Sep 25 in Missoula (our Missoula estimate).
Hardy to
Zone 2 to 7. A bare n