I grow several species. Apart from the more tender E. vanderwerwei I grow them outside with regular feeding (some extra kalium close to winter) until serious night-frost is due. Then I bluntly chop off any green (usually still quite a lot if not all) and store dry in my cellar. Repot in earliest spring (March or so, depends a little if I already see growth returning or not). Most of them, including the Sparkling Burgundy, flower yearly.
You can, however, kill a vandermerwei this way. The small bulbs may completely dry out. So they better overwinter in the pot and then they do flower every year too. I do not have a "Tiny Piny Opal" but the Meise botanical garden has a lot of E. zambasiaca cultivars which are treated much the same as mine vandermerwei: frostfree and not too dry in winter.
Ruud
