At a glance: Prairie Sensation Apple is an apple tree rated hardy to zone 2 from Ed Schultz's tree in Gallatin Gateway (winters to -50°F), not self-fertile, so it needs a different variety nearby as a pollenizer (bloom group 3 of 7, early-mid for an apple or crabapple), and it ripens about Sep 4 to Sep 17 in Missoula (our Missoula estima