The Pinetum was layed out in three stages between 1932 and 1938. A Pinetum is a garden with an extensive collection of different pines and coniferous trees from all over the world. In it's heyday the pinetum of Huis Doorn counted 160 different trees.
The money for the pinetum was raised by prominent families of the day. One such donor was count Van Aldenburg Bentinck of Amerongen. Due to a lack of resources Wilhelm requested a financial or in kind contribution on special occasions such as Christmas to purchase more trees.
It is unknown to us if the Kaiser's tree collection was driven by any scientific interest. We do know that he enjoyed compiling a variety of plant-, shrub- and tree collections. He valued both gardens, the pinetum and the rose garden. Although the latter was mainly an ornamental garden, it can be regarded as a botanical collection garden. All trees have porcelain nameplates. The oval ones indicate genus and species, the rectangular nameplates hold the name of the sponsor.
The park surrounding Huis Doorn was downsized after World War II. The number of trees in the pinetum was reduced drastically. In 1910 the remaining trees were examined by a group of dendrochronologists. They found that the pinetum still holds 40 percent of the original species of trees. Totalling sixty different species. All trees are numbered and appear on a special list.