Don't plant your Alexanders as triples. Looks nice, but not good for root systems or stability. Plant them at least a little distance apart, so the trunks have an opportunity to grow more or less vertically. My two Satakentias are about 4 feet from each other, still kind of close but they seem to like each other. Alexander equivalents (Archontophoenix tuckeri) have been given plenty of space and have grown fast.

Via Florida Native Plant Society, Eugenia Chapter:

Digg Gardens, 7430 US Highway 1, Vero Beach is now open for retail sales (almost across from Busy Bee Nursery). Owner Spencer Porteous has 3-gallon native plants in stock (& 1-gallon native plants to arrive in January). Lots of gifts for gardeners, too.