The rectangle on the left reminds us with its four corners of the four-fold cycles of nature, particularly in relation to sun, moon and stars represented by the ellipse on the right. The four corners might be taken to represent the four seasons, or the cycles of the moon, which many break down into four phases. The cycles of nature are fundamental, and necessary in any consideration of nature-derived essences.
It stands to reason that essences derived from only one season of the plant cycle will not facilitate an all-round growth experience. Rather, it takes timely exposure to the energies of new growth of spring, of full bloom of summer, of releasing and letting go of autumn, and of winter stillness to produce a balanced and lasting growth experience.