[1] The arboretum was started in 1984, as an extension of the dendrological collections of Philippe de Spoelberch, (great grandson of Elisabeth Willems) to the north of his estate of Herkenrode.

[4] In addition to these, you will find good collections of other genera such as: Betula, Carpinus, Euonymus, Ilex, Tilia, Viburnum, Quercus, Styrax etc.

[6] Many of Arboretum Wespelaar's trees and shrubs are to be found on the Red List of the IUCN (International Union for Conservation of Nature).

Arboretum Wespelaar is a part of ArbNet,[8] an interactive, collaborative, international community of arboreta.

The ArbNet Arboretum Accreditation Program is the only global initiative to officially recognize arboreta based on a set of professional standards.