We live in Northern Alabama - home of red clay. Our builder planted two 9 ft Heritage river birches in our front yard last June (2011). I have no idea how wide the planting hole was, but the trees don't seem to have been planted too deep. They have two and three trunks (clumps), and are situated in the middle of the lawn and mulched about 4-5 inches deep and two feet out from the base of the trunks (I did this, to extend the mulch out to the then drip line and keep the turfgrass at bay). The mulch forms a little "bowl" around the trunks, and does not touch them. Both trees have grown about four feet in height since last June, and are double as wide as when planted. Other than the past two weeks, we have had good rainfall, and I was careful to give them plenty of water last year after being planted. The problem I am having is that now half of the stems are bare and brittle. A branch will be mostly bare, yet have a few stems with leaves. Others have half the stems bare, and others are fully leafed out. I don't see any borer holes. My husband can't get close enough with the mower to cause damage, and does not weedeat around them, and we do not "treat" our lawn. I called three garden centers, and they all said you can't overwater river birches - even in our clay - and with all the rain I sure don't think they were underwatered! We did have a hard frost April 11, three weeks after the leaves first came out. But the branches were already bare... I thought maybe they just hadn't sprouted yet. Oh, and there is also a lot of green algae/moss growing on one of the trees. What could be wrong? And what can I do to help my trees?