Dogwood leaves curling and turning black?
Answers:
I would also suggest you check how wet the soil is around them. This could be scorch from one hot afternoon and overly drying out. It could also signal an excess of water, which may be damaging the root hairs and leading to a dryout of the top. Sounds like it is trying. Is this the first year since planting? If so, next year may be a different story altogether since it will have a better root established. I suppose this could also be disease, you may want to take some fresh picked leaves to a decent garden center to see what they have to say about it.
Dogwoods are an 'understory' plant and generally prefer cooler or partly shady conditions with adequate moisture and excellent drainage. They can be a little bit picky. They don't like it in the middle of the lawn in hot burning sun, clay soil, and as much water as it takes to keep grass lush all summer. If you ever have squishy spots in the grass after watering, it is likely to be too poorly drained for dogwood. If that is the case, less water may help.
Other answers:
try spraying them with a little soapy water and increasing the nitrogen iron supplement also trim off any infected wood and sterilize your tools as not to prpogate infection
try spraying them with a little soapy water and increasing the nitrogen iron supplement also trim off any infected wood and sterilize your tools as not to prpogate infection