Mary, the skin on my tubers tears pretty easily too, if they aren't dry enough. I've found labeling with a Sharpie designed for laundry helps since the tip seems more blunt. Even then, I don't apply much pressure. I think it works better than the ones with the fine point.
I was out of town for a week and a half. When I returned I was very pleased to see so many tubers eyeing up and some had sprouts a couple inches long. I had put a few in bags of soil and had to untangle some of the root systems that had matted together. I will be potting some up this afternoon. I continue to be amazed by how fast tubers can sprout and develop roots after receiving light and warmth. These are the best looking tubers I've had in years. Now, I'm hoping they'll grow and produce.
