So, this is Western Europe in May. It has been a dark and wet up to now. Currently we got some clear skies but it is cold.
Now I have this tree:
It is planted in soil that is mostly clay-ish and quite wet. Although last summer was exceedingly dry and hot for three months to the point where the grass was starting to die off and the soil started to crack.
The leaves do not look healthy, and some look straightforward undeveloped:
Although at the top of the tree there is a branch with nice green leaves (you can see it in the first photo, too):
I'm not even sure what tree it is, but the white-edged leaves are a normal feature if I remember well. It looks a bit like a Cornus Alba, if a Cornus Alba were a tree, not a shrub (dammit Jim, I'm a IT guy, not a botanist). But then it would be in the wrong kind of soil altogether.
Here is a close-up of the trunk. Maybe it's fungus. Other trees in the garden are also subject to lichen, except for the birch. It's shady and wet around here.