Osmunda regalis

In my fern bed the Royal Fern (Osmunda regalis) is starting to unfurl its purple/green fronds revealing the immature green spores at the tips of the pinnae. It is one of the largest and longest lived ferns preferring damp poorly drained soil. Mine are growing in completely the wrong place - bone dry dark shade under a mature oak tree which may be why they haven't grown as much as they can.