I should point out that I only have problems with the white form of I. unguicularis. No problems with other forms, or I. lazica, or I. cretensis, excepting little flowering with the last. I. lazica even survived a whole year in a forgotten black sack unplanted, when I moved gardens, and flowered fine a year later when planted. I have grown several PCI, some with ease, some less so. Brian Whyer, Buckinghamshire, England, zone ~8 ish.