Saturday, August 6, 2016

Dividing Iris

Our 'estate' has several patches of bearded iris.  To maximize flowering, the plants need to be divided every three to four years. The problem with this particular task is it best done in July or August, when the weather is at its hottest and most humid.  However, this year the flowers produced very few blooms, (a sure sign of overcrowding) and I decided despite the nasty weather the job had to be done. I tackled the two patches in the front yard last week, and today it was the back yard's turn.

Really in need of a good thinning!
Bearded iris grow from rhizomes (which look somewhat like ginger root). Each section of rhizome produces a group of leaves called a fan, with a bloom stalk in the center of the fan. Once a rhizome has produced a bloom stalk, it will never bloom again.  However, it will produce a small new rhizome. Each of the new rhizomes will produce a fan of leaves and, in time, a bloom stalk and offshoots of their own.  This leads to ever-expanding clumps of flowers, the centers of which are composed of densely packed, spent rhizomes that produce no blooms.

Spent rhizome Exhibit A
After breakfast I gathered my iris dividing equipment and headed outside. The first step was to cut the leaves back so they were about six inches long. Next I used a compost fork to loosen the clump, then broke it into small parts, lifted each one out of the ground, and tossed them into an old recycling bin. Working with one clump at a time, I removed as much of the dirt as possible so I could see what I was doing, then divided the rhizomes into pieces that had at least one fan of leaves and tossed the non-producing portions in the trash can.

The last step was to replant a handful of rhizomes.  The guides I referred to on the Internet suggested I plant each fan 18" apart.  That looked much to sparse to me, so mine are more like 12" apart.  They should have plenty of time to establish themselves before the cold weather hits.

Doesn't look like much, but wait until next year!
Five years ago today: Downside-Up and Back-To-Front

10 comments:

  1. I had no idea iris was supposed to be divided every so often! My mom planted some in my front yard several years ago and they always seem to bloom so I never paid them any mind beyond watering them.

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    1. Glad to hear that your iris are doing well. Now, though, you know what to do if they stop blooming.

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  2. That's what I don't have--a compost fork. Thanks for triggering the old grey matter back to my childhood.

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    1. You're welcome :-)

      I coveted a compost fork for many years before I actually got one. Every time I thought about purchasing one I got hung up on the cost. One day several years ago I was at an estate sale that had a lot of garden tools, and there I found exactly what I was looking for.

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  3. Really does look like ginger. Neato.

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    1. Sadly, iris rhizomes are poisonous.

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  4. I'm sure I'm due to divide mine, I did that once before.

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  5. The hard work of gardening pays off in the beauty of the flowers, right? In my house, I'm only trusted with the watering because of my past history of an epically black thumb.

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    1. I could be wrong, but I don't think you can kill iris.

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