In "The Little Prince," the baobab trees symbolize obstacles in life. In the story, the prince lives on a small planet and is concerned that these baobab trees, while they start as tiny seedlings, will grow and become destructive to his world.
The baobab trees' roots will destroy the planet as they grow. The trees symbolize problems in life, with the view that small problems will grow and become bigger issues if not addressed early. The lesson is intended to teach that problems are better handled earlier on, and are much easier to solve when they arise rather than ignoring them till later.