The "OHxF" rootstocks are better named the "Old Home by Farmingdale" rootstocks, but that is a real mouthful. They have a very interesting history. The original "Old Home" tree and "Farmingdlae" trees were discovered in an Illinois orchard where they were sufferring no fire blight like the rest of the orchard. Prof. Reimer of Oregon State University took clones home and cross-bred them. Over a period of time, many people became interested in the progeny of these two trees, but a private nurseryman named Lyle Brooks really developed them into the rootstock that they are today.