I planted this tree 15 years ago (it was about 5 feet tall then) in a south-facing alcove of the house. It has appeared to thrive in its location since then, but this Spring I noticed that the top of the central leader is bare. The rest of the tree appears healthy...plenty of blooms this Spring. My irrigation system keeps it appropriately watered. The tree is now about 18 feet wide and perhaps 20 feet tall, partially shaded by a tall River Birch in the morning, full sun in early to mid afternoon, and shade from the west two-story wing of house in mid to late afternoon.
Dieback always warrants an investigation. Here are some articles to help you pinpoint the problem:
https://www.gardeningknowhow.com/ornamental/trees/dogwood/common-dogwood-problems.htm
https://www.gardeningknowhow.com/ornamental/trees/dogwood/dogwood-leaf-drop.htm
https://www.gardeningknowhow.com/ornamental/trees/dogwood/dogwood-blight-control.htm
A rabbit chewed on the trunk but it started to heal but no leaves this year.
You can scratch off some of the bark to see if there is any green below. If there is, it is still alive.
This article should help:
https://www.gardeningknowhow.com/ornamental/trees/tgen/tree-leafing-problems.htm
I planted the tree at the end of September 2023. It was purchased through the mail and seemed to be alive when we got it. It was not full with leaves and actually only had a few straggling leaves on it. We planted it in sunny spot in our yard. The winter was mild in New York but we did get a lot rain. We are in 7a zone. It is the middle of May and the only leaf growth has been seen at the base of the tree. Will this tree grow leaves off the branches, or do you think it is in shock and maybe growth will off the branches will take another year or two? Christine
Likely, the tree is stressed. You will need to check pH, nutrient levels (over-fertilizing can be detrimental to newly planted trees.) and moisture content. You may want to perform a scratch test, as well.
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm
https://www.gardeningknowhow.com/ornamental/trees/dogwood/growing-kousa-dogwood-trees.htm
Unfortunately, it looks like you have shoots growing from the rootstock. This is below the graft point and likely not the dogwood that you started with. Rootstocks are usually more vigorous but not as appealing, but make great rootstock to attach a specimen that is slower growing to boost the speed of the process. In the case that you lose the tree, these will take over to become the new tree.
Afraid of wind and rain damage.
It shouldn't be necessary unless you live in a really windy area. If you decide to just know that it won't grow into its natural form. As they get older, branches will hang a little. Pruning keeps the tree healthy when it is done at the right time, so a broken branch, if it ever does occur, will be replaced by others.
This article will give you some information on their care:
https://www.gardeningknowhow.com/ornamental/trees/dogwood/growing-kousa-dogwood-trees.htm