White Mold Sclerotinia
Hi Several of my Hellebores have black leaves and the stems can be pulled out at the crown (friend has the same problem). I’ve had to rip out dying Sweet Woodruff that was adjacent to one of the Hellebore. In addition, my Lamb’s Ear, which is generally suffering from all the rain, has the same symptoms. And, it has just occurred to me that my Wood Poppies did not look healthy this year.
The surrounding soil has small, flat top fungi; and where the crown meets the roots there are clusters of small white “balls”. Some areas have white mold.
I have dug out and will toss all of the above.
My questions are:
Is this the right diagnosis?
Can anything be done? Soil? Plants? Fungicide?
Will it spread? (I’ll be in big trouble.)
If it can spread and a fungicide won’t help, should I be examining other plants nearby and preemptively moving them? Will moving them, even though they show no signs of the fungus, spread it?
Should I throw the infected plants in the garbage or can I put them on the curb? Thanks.
Montgomery County Maryland
This is not sclerotinia, however the photos show Southern blight. (The sweet woodruff probably has web blight.)
Search 'Southern blight' and 'web blight' on our website search.
The Southern blight recommendations include removing soil, which is a lot for most gardeners to contemplate. Do remove mulch that is keeping the soil moist. (A light sprinkling may all right later.) Since Southern blight does not usually kill roots, you may want to scrape away soil around the base of your hellebores at least. And, of course, remove all infected material.
Web blight can be a chronic problem, especially in wet years, once it gets into a bed of sweet woodruff, and you might want to consider replanting or interplanting with another groundcover.
So is it likely that the Southern Blight will spread to other plants?
I pulled out 2 Hellebores as it seemed the whole plant was infected. However, the roots seemed ok. Will it spread to the roots?
How should I dispose of the infected material? Garbage or as yard waste?
Southern blight is everywhere in soil to a small degree. The aim is to avoid an environment where it is happy. The spread would be from the sclerotia getting moved around. You want to scrape up and remove all you can find. They don't get blown around. They could spread to other plants, yes.
No, roots are not usually infected.
Do not dispose in compost or yard waste on site. Put in the trash.
So no fungicide will help I assume.
Cultural controls are recommended, no fungicides.