A bit of explaination first, please bear with me...
I ordered a couple Cascade rhizomes in March, and started them out in a small-ish pot inside to give them a head-start. Soon enough I had half a dozen shoots or so breaking ground, and eventually a couple grew to 8-10". I wanted to start getting the longer shoots trained on a trellis, so I got some half-barrel planters and transplanted them outside yesterday. But I'm worried I may have jumped the gun. I guess with the warm start we had here in Michigan this year, I underestimated how long we'd still be getting frost overnight. I wasn't up early enough to see if we got frost, but it was pretty chilly this morning. I checked the shoots, and some of the leaves look a little wilted, so I think they got a little frostbit. The main bines look okay, and the smaller shoots that haven't opened up any leaves yet look okay, and there are a few smaller shoots still just beneath the dirt.
So here's my question - should I just trim back these longer shoots that may have gotten frostbit, and let the smaller, new ones take off? Or do I just let it be, and see if these longer bines will keep going? Either way, I'll cover the pots overnight from now on until the danger of frost is over.