This Trifolium species should not become invasive in the garden, for what I see here at least. It can selfseed, but in a quite discrete way ( I never get more than a few spontaneous seedlings over several seasons)
Above all, rodents sometimes really do love eating all aerian parts of the plant, so that may limitate its expansion too
This is otherwise a beautiful plant, a bit coarse maybe, but which will find or deserve when possible its place in the bigger rockery.
