Beds are flooded to protect plants from freezing.
Sand is spread on top of the ice, approximately 3/4 of an inch thick. After the spring thaw, the sand filters down to the vines. This stimulates new growth, encourages rooting, and enables the vines to become more productive. Sanding also reduces insect populations, suppresses disease, controls weeds and fungi, and improves the bog's overall productivity. The sand actually buries weed seeds, fungal spores, insect eggs and living insects.