pachysandra blight: how to identify and treat?
Can we assume we are correct that volutella blight is our problem? • Is the lower yellow leaf(s) on plants a sign of the blight? How should we treat this issue? • For plants that appear healthy but have leaves that show more classic volutella signs- should the entire plant be removed of just continue to regularly remove the leaves when the plant appears healthy? • How does this fungus affect the plant (starts with root and then shows signs of disease on the visible plant or starts on leaves and eventually can invade entire plant)? • Is there any fungicide that will be more effective than the copper one we used? • In the bed from the photos sent (located in the back of our property and not the original area where we lost most of the plants) which is 20+ years old and very densely planted, would you recommend cutting back all of the plants now to rake out inside yellow leaves or will this further the fungus rather than treat it? Is this time of year suitable for that type of treatment or is there a better time? • Does this type of fungus affect other plants or trees? We notice that holly trees planted in the area of the front bed have yellow leaves we have never seen before. In one of the back flower beds we have seen signs similar to volutella on iris leaves as these came up and before flowering.
Baltimore County Maryland
This looks like volutella blight, a fungal disease. This does not affect other trees and plants. Most likely the yellow leaves on the holly trees are older foliage which is normally shed in the spring. Rake them up. The iris may be exhibiting symptoms of iris borer, an insect issue getting started or a leaf spot. Here is more on the iris borer. You can submit photos so we can see what you may be dealing with. https://extension.umd.edu/hgic/topics/iris-borer-flowers
Pachysandra - See our web page below for photos and more information on managing the beds culturally. If you just have small areas of affected plants, rip out and thin the plants. Removal of affected plant material, fallen debris, and clean up of old leaves etc. will also help reduce the amount of moisture trapped and will promote faster drying of the planting bed.
If you have large infected areas, you can mow at the highest setting. It would have been good to do this earlier in the spring but you can do it now. Thin out and rake affected plants and debris. It is up to you if you want to spray a fungicide. This will not cure existing conditions. Fungicides protect new foliage only. Also, check the drainage in the area and make sure the soil drains well. https://extension.umd.edu/hgic/topics/volutella-dieback-pachysandra-groundcover