Crown Rot makes for Rotten News
When you manage 21 acres of gardens and natural areas like we do at Minnetrista, the last thing you want to hear from one of your gardeners is that they found a plant disease and that it is moving fast. I hoped she was wrong. After checking it out myself, she most certainly wasn’t. It’s affecting hostas on the Minnetrista Boulevard. Now what?
In this picture you can see how the damage is moving from plant to plant.
The disease we found is generically called Crown Rot and it can be caused by three different funguses: Pellicularia rolfsii, Sclerotium delphinii, and Sclerotium rolfsii, according to the Missouri Botanical Garden website.
To develop, Crown Rot needs warm, humid conditions, not unlike what we have been experiencing in Muncie over the last few weeks. It needs these conditions to spread from plant to plant via water movement.
A close up Hosta ‘Pilgrim’ showing symptoms of Crown Rot. The Sclerotia are present.
Gardeners evidently had believed that this was a southern disease. They didn’t think Sclerotia could make it through a Mid-western winter. Too bad they were wrong.
If you have hostas or other susceptible plant material in your yard like anemone, ajuga, phlox, and daylilies, keep an eye out for these signs.
Discolored stems near the base of the plant that appear water soaked
During periods of high humidity, you may notice a white webby-looking growth that is part of the fungus at the base of the plant
Leaves will yellow and possibly collapse depending on affected species
The Sclerotia will be yellow when its younger and develop a reddish look as it matures
This look is what brought our attention to the disease.
Based on my research, it sounds like there are few options to deal with this fungus.
Remove and destroy effected plant material (not in the compost)
Dig and remove the soil to 8 inches in affected areas
Some fungicides like mancozeb might be effective
Inspect plant material before planting in your bed to prevent establishment of fungus
Sterilize all tools that might have been exposed to the fungus before using elsewhere
Here is to wishing you luck in your garden. For more horticulture tips, visit Minnetrista’s Garden Blog at minnetrista.net/blog/gardens.
Dustin Stillinger, an ISA Certified Arborist, is the Horticulture manager at Minnetrista overseeing twenty-one acres of ornamental and natural areas. He can be reached at 765.287.3563 or dstillinger@minnetrista.net.
