Doesn't sound like there's an actual problem... sounds like the plant is doing just what it should. As long as the tuber is fine, and it continues to grow, nothing is wrong with it.

Chances are, since it's young, it'll continue to do this a few times more or less before it finally starts to go into a normal leaf/dormant cycle (although I believe this depends on species of plants, age, weather conditions, etc too).

Are you worried about something in particular?

Thank you for your input, onikid. I am glad to hear the plant is doing what it should. It did not behave like this last year, with the leaves turning brown and crispy(almost immediately upon unfurling) and flaking off, but it was not this hot last year.

Last fall, I dug up the tubers and stored them in my garage over winter and they did great. This is the second season I have had the plants as the tubers have been through just one dormancy so far.

My particular worry is that the tubers might die altogether. I will just keep the soil moist and keep the plants in the shade. I hope that when fall comes the cooler weather will make the plants happier and I'll have some nice leaf growth to show for it!

Thanks!

If they were turning brown almost instantly, that might be a sign that the plant is either not getting enough water (although if their kept as moist as you say that shouldn't be the case), or it might be in an area that is just too hot and/or dry, either just by temperature or too much direct sun; at least that has been by experience.

My plants are kept in the garage at the moment, and get direct light in the late afternoon for about five hours when I open the door, and about 2-3 hours of indirect light and heat at high-noon.

Just keep what you're doing and they should be fine. If the leaf is growing and stays up for a month or more, then you know they're okay right where they are. Just inspect the tubers heavily every time they go dormant for any of the usual (soft spots, mites, etc). Good luck!