Ask-a-Dave's-Gardener: Brugmansia a/k/a \"Shredded White\"...please help!, 2 by RBLick

RBLick wrote:
I have a Shredded White Tree, which I believe in Roadrunner/Wile E Coyote-speak translates into Brugmansia X Candida. When I purchased it @1 year ago, the tree was lush with leaves and blooms; as I\'d been instructed, I planted it in partial shade here on a barrier island off the Gulf Coast of Florida (Zone 10a). The tree had been doing really well through the winter, though sadly, it’s now a shadow of what it once looked like. There are very few leaves now and the branches look shriveled up and whispy. It is very hot and humid during these summer months, though it does rain on average twice a week. The very little info I find online with regard to these trees indicates that fertilizer is not necessary, so would its poor health in fact be due to a lack of water? The blooms are (were) beautiful and I hope that I can revive it! Kindly see the photos attached; any words of advice you may have would be great! Thank you.