  We study the behavior of the normalized Ricci flow of invariant Riemannian
homogeneous metrics at infinity for generalized Wallach spaces, generalized
flag manifolds with four isotropy summands and second Betti number equal to
one, and the Stiefel manifolds $V_2\mathbb{R}^n$ and $V_{1+k_2}\mathbb{R}^n$,
with $n = 1+k_2+k_3$. We use techniques from the theory of differential
equations, in particular the Poincar\'e compactification.
