I got to admit that when first reading this I thought that it was was a typo. Being born into the metric system I get easily confused with ' and " so I could see this mistake happening to me if I was writing the text for a bulb package... or elsewhere, like as in this forum.
Anyway glad to hear that they got planted at the correct depth!
Giant is a good grower and bloomer here, stately tall blooms, but unfortunately often very floppy. Needs more sun I believe! The rain and wind we are usually having at bloom time, doesn't help either. One would think your conditions would bring out much sturdier flowers, so I hope this wont be a problem at all for you.