cassia fistula just won't grow! help
I've planted this Cassia fistula in our courtyard in the hope that it would grow and provide a neat canopy after attaining a height of around 10-12 feet. The trouble is the tree just isn't growing. I planted it some 2 years ago, and it's still pretty much just as tall and has lost most of its leaves. The ones that do sprout shrivel up, stay small and die in a matter of days. The stem has remained green, and there's no real attainment of height or girth to speak of.
The courtyard is pretty meagre as far as sun exposure goes, the neighbours have constructed a 3 storey house which means it only gets around 5 hours of sun a day. I thought it was a dearth of sunlight which was leaving the tree so puny, so I even made a sunlight reflector to see that it got an extra 3 hours a day. It just doesn't seem to be responding.
And if anyone's curious about the tree guard, it's to protect it from monkeys.
Please provide some suggestions. I really wanted this tree to thrive and have a lush canopy, it's just not happening.