I know we've all seen FL mango trees that don't want to grow due to lack of fertilization. However, I don't think the limiting factor is Nitrogen. My theory is that if one addresses shortages of the other nutrients (minors, P, K, Mg, Ca), a mango tree will grow adequately without nitrogen regardless of age.
However, if one wants Fast Growth, then nitrogen would be key. I think the more novice growers expect to see quick growth. But those of us who have had the privilege of maintaining large mango trees actually enjoy the concept of not having to trudge out the saw and chipper shredder.
The mango trees on my south lot have never been given nitrogen -- just minors P, K, Ca, Mg -- and they have been growing at what I would call a perfect pace of one to two flushes per year. Their soil is un-amended, mineral deficient, loamy sand from palm beach county. Nothing else will grow adequately without fertilization, but the mangoes are doing exceptionally well.
While Har's blend may work great on a more mature tree, young trees or deficient trees on the average joes average cared for yard will sure need some nitrogen.
Jeff - I understand what your point is with the trees growth habit using Hars blend on younger trees but you are doing something so very different than most with how you are amending/doctoring your soil.
