“Arboretum” is a word describing a botanical collection of trees and shrubs that grow in the ground. The term comes from the Latin arbor meaning a tree. Arboretum is an individual, specialised botanical garden (in Poland such gardens can be found in Rogów near Koluszki, Kórnik near Poznań, Przelewice near Szczecin or Wojsławice near Niemcza) or, and that is the case in our Garden, a part of a collection. Sometimes, as in our Garden the word “arboretum” means all trees and shrubs of a botanical garden. The part of the Garden devoted to trees and shrubs is its eastern part: from the fragment of the Temple of Divine Providence to a valley that goes down toward the Old Orangery in Łazienki Park. Some trees in the Garden remember the times of Professor Szubert, for example: the English Oak (Quercus robur), the European White Elm (Ulmus laevis) as well as old specimens of garden varieties such as Copper Beech (Fagus sylvatica 'Atropunicea') or Pfitzer Juniper (Juniperus × pfitzeriana 'Pfizter'). Michał Szubert built a beautiful Lilac alley that goes from the garden’s gate to the fountain. In recent years a collection of magnolias, especially of garden cultivars, has been expanded (now it includes over 40 species and cultivars). A new collection of trees and shrubs selected by Polish gardeners is being created. It includes for example Mock Orange (Philadelphus) bred by Antoni Wróblewski and a variety of Black Locust (Robinia pseudoacacia 'Rozynskiana') bred by Feliks Rożyński.