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Propagating Your Own Heirloom Plants

an iris division

Propagating your own plants by “long division” is a sure-fire way to make new plants. If, after a few years, you notice your Daylilies or Iris declining, try dividing them to wake up the flower power. There is no advanced planning required for this method of propagation, and no special equipment is needed. Plants that can be divided are ready any time, as long as they are not in full bloom. While blooming, all their plant energy is focused on flower performance. However, you could remove the current blooms and divide away, if you wanted. The chances of survival for plants created by division is very high since the root system for each new plant is intact and already developed.

A great time for a division session is early spring. It is worth it to stop everything go outside on a cool, overcast day. New, little perennials are just peeking their heads out of the ground, fighting off the late season winter weeds. There’s a golden moment every year when the soil is soft with early spring rains and the herbaceous plants are still small enough that your rough handling will do minimal damage to the green parts. This moment will only last a couple of weeks. Take this momentary opportunity to dig up big clumps of your favorite, old-school perennials and divide them. They actually appreciate being disturbed in this way. If left in place, they tend to die out in the center of the clump and form an unattractive donut in the landscape. Division rejuvenates them. The cool thing is, division also gives you lots and lots of free plants!

Daylilies and Iris are great candidates for division because their enlarged root systems store nutrients to minimize the shock of being ripped apart in separate sections. As they mature, they form new, thickened root structures that sprout the beginnings of new plant babies. I’m not sure exactly when this happens, but somewhere in the process, the new babies split completely from the mother plant, so when you divide them, there are rarely any cuts needed to separate the roots. You wouldn’t know this to look at them. Their feeder roots are intertwined tightly, with all the plants in a bunch, in one tight, group hug.

It is really hard to break up the loving tangle of roots, but with a little bit of muscle and some help with leveraging tools, you can do it. It is amazing how many separate plants you can propagate! One clump of daylilies can produce 25 new plants. It becomes apparent why, when left in place, overcrowding can cause a decline in the vigor of the original plant.

The thick roots are actually stems, called rhizomes. You want at least one of these specialized structures attached to at least one green shoot for each division. You don’t have to worry about them drying out for the short term. Iris and Daylily divisions are sometimes sold dry, if they are only being stored for a short while. I like to combine the division and planting in a single day, though, so the rhizomes are under less stress.

You can wash a lot of the soil off the roots to help pull each plant apart. Clean off all the dead leaves and debris. Then shake and twist each section into separate parts. The smaller the clump, the easier this is to do. Sometimes you have to take two large garden forks, plunge them into the center of the clump, and pull them apart to help break down a large mass of entangled roots. Gentle jiggling will eventually cause each plant to resign itself to a new, independent life. I don’t like to clip off the long, green stems into a pointed top, like a lot of people do to prepare their plants for sale. It seems to me I am preserving just a bit more energy for the new plants that way.

daylily division

Plant the Daylily divisions with the root crown slightly above ground. Plant the Iris divisions so the horizontal, bulb-like tuber is slightly above the soil line. I don’t plan on adding a lot of fertilizer or soil amendments to the new planting areas. Also, I know the ground will become surprisingly hard and difficult to work when the dormant season ends. It’s easier to divide and plant in early spring, when the ground is soft and fresh rains help them settle into their new homes. Ah, spring!

Long Plant Division