Sweetspire (Itea)
 

I'm in Michigan zone 5. Last fall, I planted three Sweetspire (Itea
Virginica) shrubs. I thought they did not make it through the winter, but
just recently, two of them have shown some signs of life. I can see several
new green stems with leaves branching out from the base, but the old stems
have little, if any, new leaves. The old stems still have many dead leaves
attached.

Is this typical of Itea? Should I have cut down the old stems in the fall,
or should I prune them now?

Thanks in advance!