Size up the root ball before you dig The success of any
transplanted division depends on its root system. Some divisions
fail because they don't have sufficient roots to support their
foliage. To avoid shortchanging plants of the roots they need to
prosper, I give them a wide berth when digging them out of the
ground. It's better to have more soil and roots than less. I can
shake off excess dirt, but I can't paste severed roots back on.
To approximate the size of a rootball, I place the tip of my
spade at the base of the plant and make a mark in the soil at
the end of the spade's head. This distance, 8 to 12 inches, is
usually enough to ensure that I won't dig into any valuable
roots. I pry the plant out of the ground by pushing the head of
my spade straight into the ground and pulling the handle back
toward me. Shallow-rooted plants come out of the ground easily,
but deeper-rooted plants that have the reputation for being
ornery, like large ornamental grasses, may require a bit more
effort.