how to blacken my hair without dyeing it?

Well using henna and indigo would probally work best but if you dont want to use a dye you can try using neelibhringadi oil which is coconut based with amla and a little bit of indigo in it and a bunch of other good herbs plus its all natural:)

here is a web link for the neelibhringadi oil:

http://item.mobileweb.ebay.com/viewitem?itemId=120...

I use this oil amd it really works well:)

I have also heard that jatamansi is really good for preventing grey hair.

http://www.ayurnaturalbeauty.com/jatamansi-oil/

i havent tried this product before because its really expensive but i heard it works very well!:)

Good luck and i hope i helped!:)

Reverse Your Gray Hair : http://grayhairgone.siopu.com/?szS

I'm sorry to say it but you'll have to dye it but you can use more natural dyes like henna dyes.