In 2007, I was tromping through a bog in Horry County, SC and spotted a patch of the deciduous sensitive fern that seemed much larger than the typical size plants that grew nearby. Upon planting a rhizome in our home garden, it didn't let me down, producing leaves much larger than normal. The giant 3' tall fronds (2' tall is normal) are comparable in size to our other giant Onoclea, 'Texas Too Tall', although we haven't grown the two side by side. When the fronds of Onoclea sensibilis 'Supersize' emerge in spring, they also have a nice red central stipe, whose color later fades in the heat. Moist rich soils will produce the largest size plants. Remember that these spread by rhizomes, so don't plant them near other less aggressive plants.