An extendable window structure for supporting plants has a framework, a lower tray, a middle tray, and an upper tray. The framework can be disposed on the exterior of a window frame. The lower tray, the middle tray, and the upper tray are disposed on the framework and able to move along the two sliding rails of the framework. The upper tray is smaller than the middle tray, and the middle tray is smaller than the lower tray, so the trays can be stacked together. Because plants can be placed on the trays, a vertical garden can be arranged by using the extendable window structure for supporting plants.一種可伸縮之植生窗結構,係包含一框型支架本體、一底層置物欄、一中層置物欄及一頂層置物欄,其中該框型支架本體係用以結合於一窗框外側上,而該底層置物欄、中層置物欄及頂層置物欄係架設於該框型支架本體上,並能夠上下移動於該框型支架本體之兩側滑軌上,且該頂層置物欄之尺寸係小於該中層置物欄,而該中層置物欄之尺寸係小於該底層置物欄,因此能夠移動該底層置物欄、中層置物欄及頂層置物欄,使三者能夠相疊,由於該置物欄中能夠用以置放景觀植物,故藉由相疊結構將能夠隨心所欲的配置窗外之垂直綠化景觀。1‧‧‧植生窗結構11‧‧‧框型支架本體111‧‧‧滑軌12‧‧‧底層置物欄121‧‧‧植物容置空間122‧‧‧滑移機構13‧‧‧中層置物欄131‧‧‧植物容置空間132‧‧‧滑移機構14‧‧‧頂層置物欄141‧‧‧植物容置空間142‧‧‧滑移機構
