Nothing in a Japanese garden is natural or left to chance; each plant is chosen according to aesthetic principles, either to hide undesirable sights, to serve as a backdrop to certain garden features, or to create a picturesque scene, like a landscape painting or postcard. Trees are carefully chosen and arranged for their autumn colors. Moss is often used to suggest that the garden is ancient. Flowers are also carefully chosen by their season of flowering. Formal flowerbeds are rare in older gardens, but more common in modern gardens. Some plants are chosen for their religious symbolism, such as the lotus, sacred in Buddhist teachings, or the pine, which represents longevity.