Van Gogh produced this drawing in Auvers on May 21, 1890, one of his first days in the village. He experimented in this work and also in Old Vineyard with a Peasant Woman, drawn in the same period, with various tints of blue, ranging from deep dark blue to watery light blue. This work harks back to Van Gogh’s colour experiments in drawings from his Paris period from early 1887 and also to several still lifes produced in Saint-Remy, in some of which the flowers form a simultaneous contrast with the background and in others a complementary contrast. Van Gogh produced more than 70 paintings in Auvers and only a small number of large, ambitious drawings, including this work in oil and watercolour. He began by laying out an extensive under-drawing in pencil, then filled in the sky with watercolor, leaving some areas blank for the white clouds. The rest of the scene is constructed of sturdy, flowing lines that cause the work to resemble a pen.... (http://www.tfsimon.com/auvers-sur-oise.html)