Ministry of information film encouraging people to save money with the Post Office.
Two young boys are shown. They plant apple pips in an attempt to grow apple trees. At night, one of the little boy digs up his tree to see how it is doing. The other sleeps soundly in his bed. When the boys grow up one has a "mighty fine apple tree" and one didn't.
We then see the two grown up boys at the post office. One keeps his savings in the post office, the other keeps taking them out. We see how the one who leaves his money IN has savings that grow big and strong like the apple tree.
This film was presumably made to encourage people to save money with the Post Office.