It was two years ago I got educated about a fungal disease that kills liriope.I claimed I had always thought nothing could kill monkey grass, our quaint name for liriope.

It being a soil-borne disease, I knew better than to try to replace dead liriope with live liriope. So where the lawnmower could reach, dead monkey grass became lawn. One spot was just left for falling leaves.

In a narrow strip up next to the porch, I transplanted clumps of mondo grass into the dead monkey grass.

From a distance, mondo and monkey grass look a whole lot alike and the older my eyes get, the further that distance becomes true. But mondo and monkey are not the same thing. And neither one is a grass. Both of them are sometimes called “lilyturf” but they are not lilies either.

They are what they are; liriope, aka monkey grass, is Liriope muscari and mondo grass is Ophiopogon japonicas and yes, I had to look those up. The two are not closely related, meaning the mondo should not be bothered by the soil fungus that was killing the liriope. So far it has not.

I’ve likely limited out on scientific names here, but the culprit fungus for this problem is one of the many species of the Rhizoctonia genus.

Different species of that genus are responsible for quite a few of our common plant diseases, including brown patch in lawn grass. For soybeans, we just used the shortened “Rhizoc” when we found symptoms caused by the species that favors bean fields.

Here’s the kicker and further evidence of the unpredictability of plants and their enemies; after a year, the liriope disease quit spreading right smack in the middle of flowerbed edgings and groundcover spots. Initially, the disease symptoms began on one side of the yard and spread in one direction until cool fall weather stopped its advance. That was in 2017.

Other than some sick spots finishing dying off, not much happened last year.

This spring and summer, the surviving liriope looks okay; not “Yard of the Month” caliber, but okay. And absolutely nothing was done in the form of any kind of treatment, not chemical, organic or magic.

Everything I read from every source alluded to the fact there was nothing to do. Commercial propagation nurseries have access to a couple of chemical fungicides to prevent liriope crown rot from getting started in clean soil. But those products aren’t legal for us gardeners to purchase and use and, anyway, they are for prevention, not cure.

About all we can do is to not transplant infected plants. All my liriope hearkens back to my original planting nearly twenty years ago. Plus I haven’t added anything store-bought or passed-along near the liriope sites in a dozen or so years.

How the fungi got there is just going to have to be one of those “I dunno” things that often happen in the yard or garden. Perhaps a bird’s dirty foot did it.

 

Terry Rector writes for the Warren County Water and Soil Conservation District.