Let $S$ be an oriented surface of genus $g\geq 0$ with $m\geq 0$ punctures
and $3g-3+m\geq 2$. For a compact subset $K$ of the moduli space of
area-one holomorphic quadratic differentials for $S$, let $\delta(K)$ be
the asymptotic growth rate of the number of periodic orbits for the
Teichmüller flow $\Phi^t$ which are contained in $K$. We relate
$\delta(K)$ to the topological entropy of the restriction of $\Phi^t$ to
$K$. Moreover, we show that sup$_K\delta(K)=6g-6+2m$.