By dividing rhizomes, tubers, corms or bulbs (including offsets)
By dividing the bulb's scales
From seed; direct sow outdoors in fall
From seed; winter sow in vented containers, coldframe or unheated greenhouse
From seed; stratify if sowing indoors
Direct sow as soon as the ground can be worked
From seed; direct sow after last frost
From seed; germinate in vitro in gelatin, agar or other medium