|I have a Monrovia Kousa Dogwood that has been in the ground about 1 1/2 years. Its tag says|
|Dogwoods take a while to establish their roots before they begin to grow so I think yours is right on schedule. Leaving the stake and the protective trunk wrap on for a year and a half is excessive. I'd remove both. If your tree begins to lean you can stake it again, this time using two or three stakes (opposite sides or in a triangle), set 12" away from the trunk and tie the trunk to each of the stakes to keep it growing straight. A single stake sitting adjacent to the trunk serves only to keep the trunk upright during shipping and for the first month or two after planting. Likewise with the trunk wrap. It keeps the bark from becoming damaged in transit.
Fertilizer isn't necessary, unless the foliage is off-color and pale. Otherwise, your dogwood should be happy with what nutrients are in the soil. Now that it is well established, your dogwood should produce more growth than it has in the past.
Best wishes with your landscape!