Shrub problems - part 2
I have a number of shrubs in my Takoma Park, MD yard that are struggling. Many (most) others are not. See attached pictures.
#4 - Sassafras - adjacent to thriving birch, native persimmon
#5 - Fothergilla - outer stems fine, center stems dying; mostly shady location; adjacent to thriving Viburnums, Oak Leaf Hydrangeas, River Birches, Spice Bush, (plus ferns, etc.) All plants are well watered.
We looked at your photos. There are several species of plants that are affected. This looks like a possible root issue. You did not mention how old the plants are. You may be dealing with poor site conditions like a wet poorly drained area, too much mulch, if the plants are new were the plants root bound in their container before planting etc. Did you add a lot of organic matter to the planting holes, etc. You will have to check the drainage in these areas. See our publication on these types of problems https://extension.umd.edu/sites/extension.umd.edu/files/_docs/programs/hgic/HGIC_Pubs/TreesandShrubs...
We notice a downspout in one of the photos. Check to see that the downspout is not dumping water in the root zone. If so, divert it to the lawn area. Alleviate any soil compaction and hope for drier weather. Do not overwater the plants. Make sure mulch is no thicker than several inches and keep away from the base of the plants.
Here is more information on the planting process and post planting care https://extension.umd.edu/hgic/topics/planting-process
We looked at the fothergilla photo again. You mentioned that the downspout is not dumping water into the root zone and the plant is established.
Some reasons for decline include too much moisture, too much organic matter which can hold moisture, etc. Last year we had abundant rainfall which has affected the root system of many woody plants. There is not enough oxygen in soils that are saturated and there is root loss.
At this point, scratch the branches with your fingernail and look for green tissue. If you see it, the branches are alive. If brown, they are dead. You can prune back to healthy tissue. Make sure mulch is no thicker than several inches and keep away from the stems. Check the drainage in the area. That is about all you can do.