Some take longer than others, there realy isnt a standard rule. What did they look like when you planted them? Were they sprouting already? or were the dry and shriveled?

I actually never plant them until I have them sprouting. The tubers go into plastic baggies with damp peat moss, then when they sprout, get planted into small pots, then when they are 8-12" tall I actually plant them in the ground. That way I dont waste outdoor space on duds.

Thats a good idea-one for next year. Some were sprouted, some dry looking, but had sign of sprouts. Maybe I'm impatient.

Those who are exceedingly curious about the status of their tubers can use their trowel and carefully lift the soil around the planted tuber. As soon as you see any growth, stop lifting and pat down the soil. The process will not damage the sprouting tuber if you are careful. Of course, I assume that you placed the plant tag exactly on top of the planted tuber so that you know where the tuber sprout will occur. You will find that most will have sprouted but have not yet reached soil level. You may find a totally rotted tuber too and their is no hope for that one.