That’s a tricky question. We know that virtually all the Houses of the Reach claim descent from Garth Greenhand, hence why the authority of House Gardener was so strong. (Interestingly, though, the Manderlys are not counted among the descendants of the leading children of the Greenhand, whereas the Peakes are.)
Descent from the Gardeners we have less comprehensive information about: we know the Gardeners and the Hightowers wed in both directions from the time of Garland the Bridegroom; we know Garth Goldenhand wed his daughters to the heirs of House Lannister and House Durrandon, so the Lannisters and Baratheons have some Gardener blood through the female line. And from the conflicts between the Tyrells and their bannermen, we know that the Oakhearts, the Florents, the Rowans, the Peakes, and the Redwynes have “closer blood ties to House Gardener” than the Tyrells do.
As far as the Manderlys go, we know that Garth X married one of his daughters to the Lord Manderly of his day (and another to the Lord Peake). But as to whether there were more connections between the Manderlys and the Gardeners, it’s not clear.


