Christmas tree cultivation and oxygen. Nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, copper, chlorine, manganese, molybdenum, iron, and zinc are obtained from the soil. If the necessary elements are not available in the local soil, nutritious fertilizers are used. Other important soil considerations include pH and drainage. Certain types of soil are preferable, depending on the type of tree. Pine trees are usually better adapted to a sandy or sandy loam soil, while white spruce trees and fir trees, such as the Douglas-fir, prefer fine-texture loams and clay loam soils. Some trees grow well in all types of soil, but in any case,
Douglas Cole (historian) Print". They divorced in 1983. Cole later married Christine Mullins. Cole's papers are held at the Simon Fraser University archives as the "Doug Cole fonds". Douglas Cole (historian) Douglas Lowell Cole (9 December 1938 – 18 August 1997) was an American-Canadian historian. Cole specialized in the art and culture of the Northwest Pacific Coast, and from 1966 until 1997 served as a professor in the history department at Simon Fraser University. Douglas Cole was born at Coulee Dam, Washington. His father was a construction worker and labor union activist. His mother taught elementary school. In 1960 Cole earned his bachelor's