  This paper focuses on the characterization of $\aleph_0$-categorical theories
of trees in the following sense: for any $\aleph_0$-cateorical theory $T$ of
trees there is a tree plan $\Gamma$ such that $T=Th(\Gamma(\omega))$ where
$\Gamma(\omega)$ is the generic model of a Fra\"iss\'e class
$\mathbf{K}(\Gamma)$ obtained from the tree plan $\Gamma$. Also, it is shown
that $\mathbf{K}(\Gamma)$ forms an asymptotic class, and its model-theoretic
properties have been studied. Moreover, it is demonstrated that asymptotic
classes of finite trees yield $\aleph_0$-categorical ultraproducts, and a
characterization of supersimple, finite rank trees, using the notion of tree
plan, is provided.
