Gerard van Spaendonck painted with both oil and watercolors. He contributed over fifty works to the Vélins du Roi, a famous collection of botanical watercolors possessed by French royalty. From 1799 to 1801 he published twenty-four plates of Fleurs Dessinees d'apres Nature (Flowers Drawn from Life), which were high-quality engravings for students of floral painting. Today, Spaendonck's Fleurs Dessinées d'après Nature is a highly treasured book on floral art.
