I've never grown potatoes but I do grow blueberries. The leaves on your plants, although its premature to say, are not dark enough. They seem to not be getting enough light if they are blueberries. Blueberry plants also get red branches when dormant. I go with potatoes. Potatoes tend to have light colored leaves.
Looking forward to seeing what they look like in the future. I do hope whatever they are it is a crop plant.
