Perennials that are particularly well-suited to division
this time of year include hostas (every 4 to 6 years), peonies (every 8 to 10
years), daylilies (every 3 to 5 years), ornamental grasses, and virtually all
fleshy-rooted plants that tend to clump as they mature.
Then there are the travelling plants that just keep pushing
roots out laterally in an effort to take over the world! Keep them in check
before they push through the kitchen window looking for food! These include monardas,
shasta daisies, false loosestrifes, lilies of the valley, pachysandras, and
vinca periwinkles. Dig them up with abandon. If you can’t replant the divisions
around your garden or give them away, then toss them onto your compost pile.
Back to the fleshy-rooted species: daylilies and hostas, for
example. Dig up the entire root mass of the existing clump with a shovel or
spade sharpened with a bastard file. Push the sharp blade into the soil and
remove it without wiggling it until you have circumnavigated the entire clump. It
is not as difficult as it sounds. Then pop the clump, roots and all, out of the
soil. You will literally hear a ‘pop’ as the vertical roots lose contact with
the soil that has been their home over previous years.
Now you are ready to divide. I find the easiest way to do
this is to just slice the clump like a pie, first in half, and then slice the
halves in half again using a perennial division knife, otherwise known as a sod
cutting knife. I might divide it a third time if the clump is big enough. The resulting
wedges will not take on the odd shape of a piece pie. Much to my own surprise,
the developing clump establishes itself in a very natural fashion, giving no
hints to the casual observer that you took this tather geometric approach to
the whole exercise.