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.
The high-bush blueberry (V. corymbosum) and the low-bush blueberry (V. augustifolium or pennsylvanicum), native to North America from Minnesota eastward, are the species most often cultivated, and a number of varieties are now grown in the East and West. Various species are sometimes called bilberry or whortleberry. The huckleberry of florists, sold for greenery, is a West Coast evergreen species, V. ovatum, called box blueberry and kinnikinick. The related cranberry is considered by some botanists to be of the same genus as the blueberries.