You state that when it is not raining, it recieves water once a week. I am not familiar with how much rain you typically recieve in FL at this time of year, however, the tree needs to recieve (at least in IN, it may need more with warmer temps in FL) at least 1 inch of water per week. This month, here in IN, *nothing* has needed water, as we've had over 10 inches of rain this month! (That's why I'm able to reply this time of day- it's too stinkin' wet to do anything!)
If the rope was still intact, my guess is that the root flare is buried, which is not uncommon, but is unacceptable. Did the builder (or subcontractor) give you a warranty on the tree?
If so, it was probably a year, but if you were lucky, 2 years. The tree may be savable, however, 2 months over the year warranty, in my mind, is close enough to cause a stink with them. The tree was planted wrong to begin with, which decreased it's chances for survival. If they won't replace the tree (and plant the new one right), it may be worth going to small claims to get a new one. I know we charge around $400 for a tree, installed, depending on size. Find a consulting arborist in your area to back you up in court, if necessary. I would first talk to a lawyer to make sure you have a foot to stand on, if you decide to go this route.
I may get jumped on by others for suggesting that, however, I, like many others here, am tired of other so-called "professionals" who don't plant things right and refuse to warranty them! We have had several discussions about this type of thing in the last several weeks, take a look at the rest of the threads in the Tree Care forums (mainly in the Residential and Nursery sections) and see what else we have had to say.
If the builder (or sub) can't plant the tree correctly, following typical planting details, then it is their fault that the tree has died. If you can find it in a library, see Time Saver Standards for Landscape Architecture, Second Edition, by Harris & Dines. Reference page 923-1, General Notes and Figure 923-1. This book is pretty much the bible of landscaping. Don't try to buy it--- I paid $150 for mine about 4 years ago!
In short, the ropes should have been removed, and according to the planting detail (which could go further as far as this is concerned, IMHO), the top 1/3 of the fabric should have been removed as well. It also states that "Non-biodegradable material shall be totally removed". This means the basket that is most likely still there.
There is a chance that the fertilizer adversely affected your tree. However, if it didn't flush any new growth, or at least turn greener before it turned brown, I would doubt it. In general, fertilizer won't do any good for trees and shrubs in their first year of growth, especially if it has a fair amount of nitrogen in it. You want to build the root system and not mess with the top. Once you have a healthy root system, the top should show it.
Hope this helps.
Dan
