Snow Fountain Weeping Cherry... Leaves are dying... What should I do?

by Erin
(Oklahoma)

I planted a weeping cherry approximately 3 months ago. It is situated in a small bed in the middle of my yard along with a few ornamental grasses and two tree-type roses; all are growing in clay soil and covered with cedar mulch. The grasses and roses are thriving and blooming abundantly; the tree did too, at first. Its branches were lengthening and growing new leaves. Now, suddenly, its leaves are all turning brown and falling off. It looks awful. My husband thinks it is dead... but, I wonder if it is just in shock... I continue to water it regularly (every couple of days or so) hoping it will survive. What should I do?