Here is Australia is late winter. I just purchased a lychee plant last week, it is about 3 years old and at the time of purchase I did not realize lychee is evergreen. All the leaves are gone and some cracks at the branching.
It is always sad to lose a plant or tree. However, there still might be a way to bring this plant back to life. But first you need to tell me about the current winter temperatures in your area. Yes lychee is an evergreen, however it's still a subtropical plant. So a really hard winter might case it to die... Like my Neem trees. Which too are evergreen in my part of the world. How if I took it to Europe or North America, the winter over there will kill it for sure. Anyway, now what to do, which might being this tree back to life - You first need to make a clear plastic enclosure around your plant, so light can get in, (much like a makeshift greenhouse). Then pump in carbon dioxide into it. This will be like putting a plant on a ventilator, and in my experience 8 times out of 10, the plant or tree sapling always recovers. If you don't have carbon dioxide. Then simply pump your car's exhaust into such a makeshift enclosure, (plants appreciate carbon monoxide just as much as carbon dioxide). And hopefully, it'll come back to life.
