Tree Nanny - Christmas Tree Watering Device Let your Christmas tree tell you when watering is needed. Just attach the monitoring device to the base of the tree and when the water is too low the unit plays Jingle Bells. Then use the included funnel and hose to water from a standing position. No more crawling on your hands and knees to check water levels. Avoid the constant shedding of needles and the dangers of a dry tree becoming increasingly flammable.