Cornus trees are pretty low maintenance and don’t demand a lot. They won’t need any pruning apart from pruning lower branches to create a clear and visible trunk.
Another plus is that they are trouble free in regard to pests and disease. But if you do run into problems such as disappointing colour shows during winter, it may be down to their positioning. To get vibrant stems through winter, they’ll need plenty of sun, so if they’re in a shaded spot or are sheltered by other foliage, this can lead to poor colour.