|I want to grow blackberries, but am confused about their hardiness. Some books and catalogs say zone 5, some say zone 6. Some even say zone 5 for thornless blackberries, but I've also read they won't grow here. Air temperatures here do not go that low for zone 5, but we sometimes get very bitter winds. My garden gets lots of sun and has great soil. Can I grow blackberries? thornless blackberries? boysenberries? Also, my main priorities are good, sweet taste and firmness. Size and productivity would be pluses, too. Any variety recommendations?