Hot and humid conditions do not
sound like a good time to garden. If you are a lover of iris, forget
about the weather as there is work to be done. Late July through mid
August is the best time to plant, move or divide iris. Iris is one of
the most popular perennials in the garden and easy to grow. Although
they provide pleasure for many years with little care, periodic dividing
is an important cultural practice for maintaining plant health.
As a general rule, iris should be divided about every three to five
years. Without timely dividing, the plants simply outgrow their
allotted space in the garden. Normally, the bloom quality of the clump
decreases when the plants become overcrowded.
There is no simple way to approach a clump of overgrown iris but to
just jump in and tackle it. Start by digging the entire clump. The
good news is, the plants have a fairly shallow root system so digging
deep is not needed. If conditions are dry be sure to water one or two
days before to moisten the soil for easier digging.
Once out of the ground, start breaking the plants apart. Iris
rhizomes are vigorous and almost indestructible. Knock the soil off the
roots and break and pull the rhizomes apart. There will be more
divisions than anyone could possibly use so discard small roots. Iris
rhizomes grow out. The old rhizome furthest away from the fan of leaves
discarded. All that is needed is the
last knee or bump attached to the leaves. The rest is old unproductive
rhizome that is not needed for a healthy plant. Many prefer to cut the
leaves back about one-half to make the plant more manageable.
The hard part is now done; replanting the iris rhizomes is easy.
Prepare the soil by spading an ample supply of compost or peat moss to
help break up the hard clay soils commonly found in our area. Iris
rhizomes should be planted very shallow. Cover only the bottom half of
the root and leave the top exposed to the sun. A nice size division, or
start, is a grouping of about three prepared rhizomes. Point the leaves
outward in a circle and lightly cover. Thoroughly water and the process
Sit back and wait until next May for a wonderful reward of iris
blossoms. Enjoy one of the areas easiest to grow perennials, as there
is nothing finer than a graceful iris blossom.