A DC electromagnet is simply a coil of wire connected to a DC voltage source. It can have an air core or an iron core.
Northern Highbush Varieties. High Chill Varieties. Northern Highbush varieties are the most widely planted blueberries in the world. They grow best in temperate climates where total winter chilling is 1,000 hours or more.Except where listed, most Northern Highbush varieties are relatively self-fertile.orthland is the one of the most cold-hardy Highbush varieties. It is vigorous, easy to grow and adaptable to different soil types and conditions. Northland yields are heavy and the berries are sweet with high sugar content.
Varieties of Blueberries: Arlen Blueberry-This variety is a good choice for the warmer, southern areas of the U.S. Berries are medium to large, light blue and attractive. Arlen blueberries are good fresh with fine flavor, firmness and appearance.Height: 5' - 6'.orthsky Blueberry-This variety is the most cold hardy of all the blueberries, and is most productive with winter snow cover. Small, sky blue berries are firm with a wild blueberry flavor. Northsky needs another blueberry variety for pollination.