Christmas tree cultivation species are grown as Christmas trees, although a handful of varieties stand out in popularity. In the United States, Douglas-fir, Scots pine and Fraser fir all sell well. Nordmann fir and Norway spruce sell well in the United Kingdom, the latter being popular throughout Europe. Like all conifers, Christmas trees are vulnerable to a range of pests. The final stage of cultivation, harvesting, is carried out in a number of ways; one of the more popular methods is the pick-your-own tree farm, where customers are allowed to roam the farm, select their tree, and cut it down themselves. Other farmers
Knagenhjelm (noble family) Manor ("Kaupanger Hovedgård") in Sogn og Fjordane and are included in the Yearbook of the Danish Nobility ("Danmarks Adels Aarbog"). Before he became noble, Niels Tygesen Knag had only a tree trunk as his arms (Hans Krag. 1942). The coat of arms was received upon the ennoblement in 1721. Description without the heraldic terminology: "On a blue shield a tilted, chopped and knotty silver tree trunk beside or above which there are three golden stars in each of two bends. On the helmet is a six-pointed star between two buffalo horns divided in gold and blue, vice versa, respectively." Some