Q.Dieback – pruning central stem
The top half of my young Cornus controversa died after presumably insufficient water in summer (we are now in winter).
If I prune the top half out will the tree continue to grow in a nice structure or should I start again given it is a focal point?
Certified GKH Gardening Expert
That actually looks to be a fungal dieback. It may have contracted a fungus from the soil. This is usually caused by too much water, and usually when trying to compensate for dry weather, but if the tree did not get sufficient water then it was likely already in the soil.
You may want to go ahead and use a fungicide on the tree and soil to prevent future dieback. This article will help: https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
The tree will never grow into the exact same shape as it was, but these trees have a tendency to sprawl out and branch over time anyway. You can likely select new leading branches and keep others pruned away until you reach your desired shape, or you can leave it to form a more "shrubby" tree.
This article will offer more information on this particular cultivar: https://www.gardeningknowhow.com/ornamental/trees/dogwood/growing-giant-dogwood-tree.htm