Sunstick measures the amount of sunlight a given area receives in one day. Simply attach a flower-shaped sunshine meter to a stem, plant it in the ground in the morning and return at the end of the day. It determines the full shade, part shade, part sun and full sun areas of the yard to match the right plant with the right location. You"ll get better and more beautiful results by planting in the right place the first time. Each meter is single use. After testing, simply match the color of the sunshine meter to the corresponidng color on the included chart. Use when trees are fully leafed out. Includes 3 sunshine meters and 3 stems.