A cutaway showing the root system of ornamental grass.
Miscanthus grass is a nice looking ornamental grass, grows 6 to 8 feet tall, provides movement in the garden, great planted as a specimen, or in small groups, sends up feathery plumes in the fall, and is great for winter interest, BUT is hard to divide! To read more about how to divide it click
The first time I ever saw Miscanthus grass was at Green Animals, in Newport, Rhode Island, about 18 years ago. Green Animals is a historic house, that is owned by the Preservation Society of Newport County. What I initially liked about Miscanthus grass was its billowing movement, they were tall and showy, and added a kind of tropical look to the garden.
Upon returning from vacation, I went to my local garden center and they had two varieties of Miscanthus grass, Morning Light and Autumn Light. I bought three morning light, which I planted about 10 feet apart, in a day lily bed, that has 27 different varieties of day lilies in it. To COUNTER BALANCE them on the other side of the property, I planted two autumn light, in the lawn. They float out in the grass, like sculptures.
The grasses liked where I planted them, and grew just fine. BUT after a few years passed, I noticed the centers of the grasses were starting to die out. The grasses were starting to take on a Christmas wreath shape, a green ring of growth on the outside, and an empty center. As the years passes, the wreaths of grass got bigger, and bigger, and more and more of the centers died out.
I got my grasses when they were just starting to be seen at garden centers. I don’t think, at that time, a lot of people really knew that much about their growth habits.
A few years, after first seeing the Miscanthus Grasses at Green Animals, in Newport, I again returned to that garden. The grasses were gone. I asked a gardener there, and he said they felt the grasses were really not something that the original owners of the house would have planted, so they took them out. He then said it became a big project, and they finally lifted them from the ground with a backhoe. That was a scary thing to hear.
After that, while on a Lenox Garden Club, garden tour, in Williamstown Massachusetts, I saw Miscanthus Grass on an estate, that was open for the day. I asked the two gardeners there, if they ever tried to divide the BIG specimens they had? They said NO, but heard it would be a big project. They also told me, if I could not divide them, spray them with Roundup, they would die, and over time, the root system would rot away.
One early Spring day, after cutting them back, as close to the ground as possible, with electric hedge clippers, and before any spring growth emerged, I decided to try dividing them. I was successful, but it was a BIG JOB!
First of all, the root system of the Miscanthus Grass only extends out from where the plant grows up from the ground about two inches. The THICK and DENSE root system extends down into the ground about 12 to 16 inches. Even though the center of the grass dies off, that root fiber still stays solid. The root system of the Miscanthus grass is like a weighted base, that keeps it from not blowing over.
Wearing safety glasses, for eye protection, and kneeling on a flattened cardboard box, I took a hatchet, or small ax (that my grandparents used on their farm, and my father used, and I was now a third generation using their tools), and started to try to chop a pie shaped wedge, out of the grass. I worked from the outside edge toward the center. I then used a straight spade, shovel, and prying bar (all once belonging to my grandparents), and started to pry out the first piece, of the “grass stems and root system pie”. Prying out the first piece was the WORST! But every piece, after that became a LITTLE easier.
After prying out a piece, only keep about 10 to 12 inches of the outside edge of the grass. That is the ONLY part of the grass that is alive. You will replant that piece, and your new grass will come from that. Don’t be afraid of hurting, or killing the outside edge of the grass, it is really sturdy, and will not be harmed by you hacking at it. Throw away all of the dead part, from there to the center. It all depends on how often you divide your Miscanthus grasses. I let mine form FOUR foot wide “wreaths” before I divided them. A FOUR foot wreath will give you many divisions to give to friends. It took me two days to divide three Miscanthus Grasses.
If you have a chain saw, you could try cutting through the grass’ root system with that. It would probably save you a lot of time, and energy.
And finally, when replanting your NOW new division of Miscanthus Grass, amend the soil where you initially had the old plant. The old plant probably depleted all the nutrients from the soil that it sat in. If you never planted Miscanthus grass before, SPACE them far apart. A grass that is THREE feet wide at the base, can easily be TEN feet wide across its top. Also think about other plants in the area, that will be shadowed, encroached, and have to compete for space with a plant that can grow quite tall and wide.
So tell me if you ever divided Miscanthus Grass? What was your horror story like? Do you have an easier way to do that job?
Companion Posts…
When Designing a Perennial Garden it’s ALL about the Shapes of Leaves 1-15-2011,
Colored Foliage adds that WOW FACTOR to a Garden 2-22-2011,
Stagger Plant Heights when Planting (Designing) a Garden 2-23-2011,
Roses..Planting, Pruning and General Care 5-11-2011,
My Hydrangeas Don’t / Won’t Bloom is a Lament uttered by Many 6-21-2012,
Starting a Rose Bush and other plants from a Cutting (Slip) 6-17-2011,
Growing a Topiary from an Upright Yew 6-15-2011,
Neatening up a Rhododendron after it Blooms 6-3-2011,
My Peonies Don’t / Won’t Bloom 5-16-2011.
Fred Gonsowski Garden Home 
****Hi there Everyone**** If you have a moment, the nice people over at the San Francisco Chronicle used this post as a Resource for one of their articles. Here is the direct link http://homeguides.sfgate.com/propagating-miscanthus-landscaping-36726.html
glussenden says…I developed a way to divide Miscanthus. I was drawn to this blog by the perfect drawing of a Miscanthus needing dividing. Very Helpful! You need a spade, and a long handled one at that. Shovels will not work, the steel blade is at an angle to the wooden handle. Very good for moving soil, but cannot cut straight down. Sharpen your spade on a grinder so it is like a knife (see description of Miscanthus roots in the article). Put on heavy boots with stiff soles (my Aslo hiking boots). Refer to the drawing in the article. Foliage must be cut down, as in late winter, but may be growing new leaves…Cut out the parts you want by JUMPING repeatedly on your sharp long handled spade to cut through the roots to the full depth of the blade. Then dig out the divisions. You must have good balance to do the jumping bit and be fit to do any heavy digging, but it is not really all that hard when you consider that this is all done without bending over and utilizes your body weight (and a sharp spade to cut the wiry roots). I think I work just as hard dividing Achillea, by the time I get off my knees having carefully replanting all those little bits. Miscanthus divisions are indestructible.
glussenden, Thank you for your comment on Dividing Miscanthus Grass, that you posted under the Post Commenting on a blog, it’s easy! I moved it to its proper place, for all to read.
Ha so funny, just did a big one today. My key tool was a reciprocating saw, I sawed through the crown patiently straight down into the soil with probably a 9 inch blade. Of course I dug around the edges. After a few passed with the saw, I could use a garden fork and then spades to separate the root mass into four clumps. Amazingly tough stuff. I even used the saw to help underneath the clump as I was lifting out with the fork. Worked well, but a lot of effort no matter how you do it.
Keith, if the Reciprocating Saw can take down a house, it should be able to cut through the Miscanthus Grass root. Your idea is another great one, that readers could consider, when taking on that job. Thanks for commenting! There are PROBABLY a lot of guys and gals out there, that have the saw, and would never have considered using it. ONE think thought, WEAR PROTECTIVE EYE WEAR!
How long does it take for the root system to rot enough to till the ground for another crop, after killing with roundup?
Hi Don,
I never killed mine with RoundUp. That was suggested to me, by a head gardener, at an estate in the Berkshires. The root system, if not dug up, would take years to break down. It is really hard and dense. If you killed the plant, and left the root system there, I would suggest planting something around the dead root system that would get big and could drape over the dead spot. You could also put a large clay, or metal pot on the dead root, and plant something in that so you would get height in the garden. Grasses are lovely to look at, but are not an easy plant, when it is time for maintenance. GOOD LUCK, and have a nice Summer! .
Good info, thank you. I have a Miscanthus that will need dividing next spring. I think I shall enlist my husband’s help he is wicked with a sharp tools.
When I originally commented I clicked the “Notify me when new comments are added” checkbox and now each
time a comment is added I get three emails with the same comment.
Is there any way you can remove me from that service? Bless you!
Hi there Martiza, I can try putting your comment in the trash and that might do i, but if it does not work I can make you spam, but you will probably not be able to comment again. But you could try after I make you spam, and it might go into a holding place, and then I can let you on again without you getting the pingbacks. You be the judge and tell me what way you want me to go. Sorry for the inconvenience.
I do not even know how I ended up here, but I thought this post was great.
I don’t know who you are but definitely you’re going to a famous blogger
if you aren’t already 😉 Cheers!
Masonry, thanks for you lovely comment.
Hi Fred, I have three which need to be separated. I found your site quite helpful. The plants have only been in my ground for 2 years, but are very large when fully grown. I love them and plan to move parts of them to conceal my propane tank. By the way……are we related?
Hi there Brenda, we are probably not related, as my grandfather and his brother had girls, and my father was the only boy. I’m the last of my line with the Gonsowski name. I did meet once, some Gonsowski’s that were from the Connecticut shore area by Mystic, but their stories were not anything that my grandmother ever mentioned.
Hi, yes a sawzall works wonders on miscanthus and Annabelle hydrangeas. I use the ‘Axe’ blade. Don’t forget to call Diggers Hotline!