The problem is lowering (or blocking) the production of DHT is not as black and white as some people suggest. The most known "natural DHT blocker" is Saw Palmetto and honestly, you'll probably get mixed results if you only use that.
Some people (probably less than 2% of the male population) could get away with a Ketoconazole shampoo like Revita and Saw Palmetto but for the other 98%, it is not nearly enough. Instead of going "the natural way", why don't you try Minoxidil for a little while and see how your hair/scalp react?