High hanging potted plants can be difficult to reach. To water them, you have to pull up a chair every time and make sure that the water doesn't drip out of the watering can.

 

Instead of balancing with a watering can, you can place a handful of ice cubes in the flower pot. The ice gradually melts and waters the plants without dripping excess water.

Real Christmas trees can also be watered in this way, as it is often relatively difficult to get to the tub in which the Christmas tree is standing.