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.
With hundreds of types of blueberries available, the cultivar fruit taste can vary from tart to sweet. If your bushes are intended to produce tart or sour fruit, you may want to select new cultivars.