I've never cut one and have had scapes show up after they've only been planted a day or two. I received 'Christmas in Oz' via the LA and planted it on April 28. A double fan and the 2nd of those fans has a scape as of yesterday and the scape on the first one is now about 8" above the cut foliage. I won't cut them. I have had some scapes like that abort naturally, but most go on to bloom, though with shorter scapes and reduced bud counts from what the registration info indicates. I tend to think the plant will do what it can without harming itself. If it's too much, then the plant won't grow it. I've certainly not seen any evidence that leaving the scapes affects future growth or bloom. I'm growing them in containers and even some that have only been there two years have increased enough they probably need thinning.
