Four years ago we planted two beautiful profusion crab apple trees on either side of a bradford pear tree. Both trees have done really well with plentiful blossoms and beautiful green leaves. This year they both blossomed with their pink flowers, but only one has a full compliment of dense green leaves. The other although it did have blossoms, now has only a scarce leaves and mostly bare branches. I can not see any signs of pests or fungi though it does look as though some branches were damaged by the harsh winter. Is it possible the leaves will arrive later in the spring or summer? Or am I better off looking at replacing it now so it has a chance to establish itself he fore next winter? Thanks so much!
Check around the base of the trees for mouse or rabbit damage. If the bark has been partially stripped off by them eating it over winter then it can cause some of the problems you’ve been describing. If the bark has been stripped of all the way around the trunk then it is fatal. Also check to make sure that you haven’t piled soil or mulch up against the bark of the tree. Scrape away and bark or soil until you see the original soil that the tree came in. Burying the crown of the tree (where the trunk enters the soil) also slows or stops the flow of moisture and nutrients from the roots to the branches. The fact that they flowered and have some leaves is hopeful. Winter was indeed harsh so they are under some stress. I’d give them a chance to recover before ripping them out.