Divide & Conquer?

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A few weeks ago I talked about the propagation of plants as one way to economically increase the plantings in your garden. <http://www.welchwrite.com/agn/> Division is another way to accomplish the same task. Turning one plant into many is getting something for nothing. This is a good thing that we can all understand. In my case one of the few divisible plants I have is the Iris. Scattered throughout my back garden are many varieties, but few of them have ever bloomed. Occasionally I am surprised with a brilliant purple bloom here or there, but most only mark their presence with spiked green leaves.

This lack of bloom can be caused by a wide variety of reasons. In some cases the plants are in such a shady area that it is all they can do to grow foliage, let alone flower. Other areas are watered much too little. Iris' like a moist environment. After all, they are found natively in marshy areas, not the temporarily reclaimed desert of Southern California. Finally, and most importantly, I don’t believe that any of the iris in my garden have ever been divided. According to my reading, unless iris is divided regularly they will eventually crowd themselves out with twisted roots.

Rejuvenation

My first step will be to locate all the iris, dig them up and transplant them together in an area more hospitable to their happiness. More than likely, this will be the bed just off the back patio. This bed already has a few iris along with Agapanthus and Nandina. A few years ago I installed a soaker hose in a loop throughout the bed. This allows me to provide just the right amount of water to this area.

When we first moved in 3 years ago this bed was fronted with a riot of purple mums. Unfortunately, these mums died off over time leaving a fairly large bare area. Grouping the iris here would really help to rehabilitate this area and provide a nicer view from the rear of the house to entice guests (and ourselves) out into the garden.

Once I start digging up the existing iris I will have a better idea which ones need dividing. Iris are a rhizome which grows horizontally at or just below the surface of the ground almost like a larger version of rhizomatic grasses. Use a sharp knife to slice rhizome into fairly large pieces making sure that each division contains some roots and some green leaves. Discard any deformed or rotten rhizomes to insure you don’t spread disease. Transplant the rhizomes just barely below the soil with the fan of leaves pointing in the direction of future growth.

Many bulb and bulb-like plants can be divided in a similar fashion. A few years ago I divided a large clump of Fortnight Lily (Dietes vegeta) into some healthier and more manageable transplants. Division is usually done in the autumn and you should wait until the current foliage is completely brown if the plant is not evergreen. Here in California the Fall brings cooler temperatures that put less stress on new transplants. You want to give them every advantage so they can re-establish themselves, even if you are planting in the same hole from where they were dug. Check with your favorite garden reference book for more detailed instructions.

More plans

As always, one project leads to another. I would be interested in hearing of your successes or failures with both Clivia and Cyclamen in shady areas. I have been looking at various ferns, as well. My local nursery regularly has specials on these plants and I am constantly looking for shade plants that can fill in the blank areas of the back garden. Send your comments to the AGN mailing list. IF you are not already a subscriber you can join by sending a blank email message to agn-subscribe@onelist.com. Any other gardening hints are always welcome. Sharing our knowledge helps us all develop more beautiful gardens.

Keep Digging!

Douglas