Q.Black Tips On Dogwood Tree
The tree appears to be healthy, but the leaf tips are turning brown/black. What is causing this? What can I do ?

Certified GKH Gardening Expert
This can be caused by too much fertilizer, or too much water.
You will want to treat the area with a fungicide, just in case. This article will help:
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
Make sure that the soil has a chance to dry out thoroughly down to about 3 or 4 inches between watering, then give them another very deep watering. They can tolerate dry soil better than they can saturated soils.
Here is an article that will help you with their care:
https://www.gardeningknowhow.com/ornamental/trees/dogwood/caring-dogwood-trees.htm