Hi Catharine, >> My feeling with many of the Russian and other so-called "cold resistant" varieties is that they are resistant to temperature swings more than just able to set fruit at lower than normal temps.<< I think it is more than coincidental that many of those varieties come from the area of the Altai Mountains, where temp. swings are obviously common. "Gregori's Altai" is also one of my premier hot weather varieties. "Grushovka" might be better known for heat tolerance if it wasn't determinate. <G> That's also a favorite with my wife's nursing home residents. It's about the right size for an ole person to eat out of hand without making too much of a mess. I send several bushels of "Grushovka" there each year.