Here are some good tips to keep your Bonsai healthy all year round.

Also if your Bonsai is placed against a wall make sure you turn it around
every two weeks. If you don't turn your bonsai every two weeks it may grow out of shape as it
grows towards the light.

Another overlooked point is to make sure you don't  place a bonsai pot directly onto concrete if it will be
subject to direct sunlight for long periods. The heat generated off the concrete coupled
with the small amount of soil in a bonsai pot can bake the roots of the tree and kill it.