Kelp is a large underwater plant that accumulates a number of nutrients. It is used in food supplements for animals and humans, cosmetics and a variety of other uses. For plants kelp is used as a foliar spray and as a soil amendment, compost ingredient or irrigation feed. Wet seaweed gathered on the beach, washed and composted, can be a good biological source of potassium and a wide variety of trace elements, including ingredients that can improve soil texture and tilth. Kelp also contains relatively concentrated amounts of plant auxins, growth regulators and stimulants, gibberellic acid and cytokinins. These components promote plant health in a variety of ways from root stimulation of transplants and cuttings to delaying decay in mature crops. Most commercial soluble aquatic plant products are based on the kelp species Ascophyllum nodosum, harvested from the North Atlantic off the coasts of Canada and Norway.