Most likely the lucky grower will find that it will get very cold before the plants completely mature (which Stoner seems pretty accurate about determining.) Be prepared to protect your plant(s) from the cold, and snow, if you want to keep the harvest. You're going to have to be inventive, especially if you have that thing in the ground (did anyone tell you that growing outside is probably illegal for you?) You may need a lot of plastic, a weather-resistant heater, or maybe you'll get by with "water walls" (I doubt it.) If you're really industrious, you could build a leanto or something over it to help retain heat and not get snowed on. Expect a snow or two, and at least one good cold snap before you get your harvest.
Oh, and most of the quality comes from harvesting correctly. Too much to go into here. Get a book if you don't know. Cervantes is a good source.
Don't ask me why I know these things. :-)