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.
Most types of southern highbush require between 150 to 800 chill hours, which is usually easily met by most zone 8 areas. The Jubilee cultivar (Vaccinium corymbosum Jubilee), for example, requires 500 chilling hours, while the Misty cultivar (Vaccinium corymbosum Misty) requires only 300.