Hi, I've never noticed a difference in height of MG's and to be honest have never measured. My arches are a little under 6 feet tall from the ground to the top. The cages come up to about my hips, maybe 3 feet? with about half a foot buried. the MG seeds are always the last to be started indoors because they come up fast and want them in their permanent home before they get to the twining stage - a few weeks after true leaves start appearing.