Growing Apricots in the North
Apricots are much hardier than most people think. The dormant trees tolerate cold temperatures as low as -20° F, or a typical USDA Zone 5 winter. However, because they have a low chilling requirement (400 to 900 hours), they respond to any warm period in late winter or very early spring by bursting forth with blossoms that are then easily killed by a frost. The longer you keep the trees from blooming, the more likely it is they'll escape a late frost.
Make Them Bloom Later
To encourage your trees to bloom late, plant them where they'll stay cool in the spring. The north side of a building is a good location. Set the tree where it is shaded in the spring: as the sun gets higher in the summer, it will get plenty of light. You can also delay blooming by mulching the roots heavily in late winter so the soil will thaw later. Some years it may be too cold for bees to be out pollinating when apricots bloom, which could limit the crop. Some smaller insects do come out and pollinate blossoms whenever temperatures rise even for a short period. Because these insects don't fly very far, you may consider planting a few apricots closer to each other than the 25-foot distance usually recommended.
Although most apricots are considered self-fertile, some, especially several of the hardier ones such as 'Moongold' and 'Sungold', are not, so check carefully when buying or ordering trees. You may need another variety for cross-pollination. Standard trees can grow 20 to 30 feet tall and can live up to 75 years or more in ideal climates. In the North, where the trees are under unusual stress, they'll probably survive about 15 years (more if the climate is favorable) and grow to be about 20 feet tall.