Magnolia tree's top partly biggest trunk seem late.Lower branches flowered,leafing out. Can this tree be save? Planted 4 yrs ago, last spatter main trunk leaves died rotten...

Planted 4 yrs ago, last spatter main trunk leaves died rotten early. Lower branches leafs stayed on til crash down. the tree has the largest trunk, healthy limb coming off it that flowered, leafing out this spring above the lower limb there be no flowers, not leafing out.
Answers:    YES evergreen fertilizer spikes at the drip line and lots of marine mine is 5stories tall 50 ft and have the same prob, not as unpromising but looks great now
YES ! adjectives you need to do is hold a hose pipe on next to it for around 9 - 12hrs i have tryed it it works from expierience