Here I am on my way to plant a branch of weeping curly willow. You see, willow is one type of tree that grows pretty much exactly the way very young children imagine trees to grow-- you stick a branch in the ground, water it, and it becomes a tree. It produces some enzyme that promotes rapid root growth--you can in fact put a sprig of willow in water with cuttings of other plants to get them to root faster.
You can score a few vertical cuts into the bark of the base of the willow cutting to hasten the rooting process. The tissue damage promps faster cell division and speeds things along. Willows are fast growers, so hopefully I'll have a tolerably-sized tree in two or three years. Below is a picture of what the branches of a mature curly willow look like:
