It depends what type or breed of lansones you got; i have a native one back home-it took 10 years to bear fruit, i bought LongKong Lansones(my personal favourite) propagated by Inarching (highbred from Gloria Farm-fruits cost 250-400/kilo) and i was told it takes 5 years to fruit...

My LongKong- i only have 2 trees seems to be unhappy since i move her twice!! and soil is a bit poor..I was told that it grows better in between Rambutan or other fruit trees as it needs shaded area. I just put cowspoo/sh*t yesterday i hope it will work.

My Tuod Mango 4 meters high 4years old bears fruit 8 pcs. last year..no fertiliser same poor soil on sunny and windy ground but we put cowspoo on it.