I have a Giant calla lily in our garden. This thing acts like it's on steroids - it just appeared in our yard 2 years ago and now it has 40+ leaves and is 4 feet tall. I think it is the "common" giant calla: white flowers, no spots on the leaves.

Anyway, I would like another huge calla and am wondering if there is a way to divide the rhizome without digging it up. It doesn't seem to seed. It never goes dormant. I have no experience dividing plants and would hate to screw this up and lose the calla.

Btw, there does seem to be an offshoot - a younger-looking part of the plant with smaller leaves. Is it possible to transplant the offshoot without disturbing the mother plant?

Any advice or resources would be greatly appreciated.