September is Ideal for Planting and Dividing
September is an ideal month to plant because the temperatures are usually starting to lower and the rains are starting to return. Also planting or dividing now gives plants time to establish before winter sets in. There are a few plants to note that don’t do well when planted in the autumn including coralbell (Heuchera sp.), Japanese anemone (Anemone xhybrida) and red-hot poker (Kniphofia hybrids ). These plants have a tendency to frost heave (push out of the ground) due to fluctuating winter temperatures. They are more successful with spring plantings.
Division now is particularly suitable to spring and summer flowering perennials. You know a perennial needs division if there is a reduction in the flowering or the vigor of the plant, a hole develops in the center, or there is a “traffic jam” appearance to the stems.
One of my favorite quick and easy methods of division, that I learned over 25 years ago (yikes!) while working at the Kalmthout Arboretum in Belgium, is the double-fork method. This is great for large thick clumps of plants, such as Shasta daisy (Leucanthemum xsuperbum), hosta, daylily (Hemerocallis) and border phlox (Phlox paniculata). To divide clumps using this method, first lift the entire clump from the ground with a spade. Then insert on spading fork into the center of the clump, and insert a second fork parallel to the first, setting the forks back-to-back with the tines of the two forks intersecting. Pull the forks inward and then out-ward, and the clumps will separate in two. You might have to repeat this process several times with a large clump. Once the large clump is broken up, a sharp nonserrated knife can be used for further divisions to obtain smaller pieces. Perennials such as peonies, which are fleshy rooted, do not divide well with the double-fork method and are best divided using a knife.
Here’s a quick video on this subject:
I cover division and planting in detail in my book The Well-Tended Perennial Garden and you may have heard us discuss this topic on Martha Stewart Living Radio on Sirius Satellite for the Living Today show with Mario Bosquez on Monday September 8, 2008. You may have tuned into the new show Daytime Columbus on WCMH-TV, Channel 4 Columbus, NBC4I.com, with Host Gail M. Hogan on September 23, 2008 where we demonstrated the double-fork technique and discussed follow-up considerations with soil and watering. If so, welcome to the website!