Muay Thai practitioners are known for having iron hard shins. Students regularly ask us how they can condition their shins for Muay Thai.
Kicking Trees- There is a persistent myth about kicking trees so achieve hardened shins for Muay Thai. It is possible that at some point in human history there was someone that kicked banana trees for shin conditioning. Banana trees have a more plant like trunk with a fair amount of give so one could potentially kick one. However, it is unlikely they were ever used regularly in shin conditioning outside of 1980s Van Damme movies. While in Thailand every Thai I spoke to laughed about the absurd idea of kicking a tree for shin conditioning.
Many Thais start training between 8 and 12 years old, then begin competing professionally between ages 16 and 22. They spend around 6 hours per day kicking heavy bags, Thai pads, and other modern equipment. After 8+ years of 6 days per week 6 hours per day kicking their shins are conditioned like iron. When I was in Thailand I did the normal Thai routine of 6 hours per day 6 days per week training. During this period my shins got significantly tougher from the constant kicking.
There is no short cut to tough shins. You must put in the time kicking pads and heavy bags if you want hard conditioned shins. In the end there is always some pain from shin on shin contact. As far as that is concerned you will just have to suck it up buttercup.