I am a novice gardener so please bear with me. I received some potted dahlias last spring, I planted them in my yard and they did very well. So, yesterday I dug up the tubers and now I have a few questions. Do I split the bunch of tubers apart of leave them in a bunch? Should I snip off the roots at the end of the tubers? I think I am ok as far as storage over winter, but in springtime can I start them indoors or should I wait until after the first frost? I live in Northeast Pennsylvania,I think that is zone 6. Thanks for your help!