During the last six or seven months of 1889, Van Gogh did at least fifteen paintings of olive trees—a subject he found both demanding and compelling. He wrote to his brother Theo that he was "struggling to catch [the olive trees]. They are old silver, sometimes with more blue in them, sometimes greenish, bronzed, fading white above a soil which is yellow, pink, violet tinted orange...very difficult." He found that the "rustle of the olive grove has something very secret in it, and immensely old. It is too beautiful for us to dare to paint it or to be able to imagine it." - National Gallery of Art