I only have C. moorei 'album' here and over a 10 year period it had developed into a massive clump with 2.5+ ft high necks and monstrous 12" diameter bulbs all above ground level. Last winter was the coldest here for 25 or so years and the bulbs were reduced to mushy piles of brown detritus. It was tempting to rid myself of the debris, but I left everything as it was and by the end of May, tiny green leaves appeared from between the rotting scales of the former bulbs. Over the summer, these new growths have gradually increased in vigour and although the leaves are nowhere near as long or wide as last year, there's a flower spike that has just opened a flower over the past few days. The remnants of the former clump wil be lifted next spring and buried deeper in the hope of a return to normal. I hope I don't do my back in - the adjoining rhizomes seem pretty hefty and very deep rooted despite last winter's damage.