Normal hair usually grows about a half inch a month. You can take herbs like horsetail, salmon oil, vitamin E.

Well that all depends on how much work you want to put into your dread locks, if you start your dreds with 2 inches of hair, then you will be putting a lot of work into them but they won't really look like dreads. If you start your dreds with 5 or 6 inches of hair then you will have a much easier and rewarding experience with making dread locks.

You don't have to shave your head. There are a couple ways to get dredlocks out, if you haven't used a dread perm
1. The Easiest way: cut your dreads off a little below root and have about 2 inches of hair. You won't have to spend hardly anytime with this, and if you are not partial to your hair then this is a good way for you to do it.

2. Cut the first half of your dread off, from the tip of the dread to the middle. Then soak the rest of the dread in conditioner and comb the dread out. This will take some time, but you will have cut the strongest part of the dread off, so it will be a lot easier to comb the rest out.

3. You just love your long hair and don't want short hair: I can completely understand this, this is probably the way I would choose if I were ever thinking about cutting my dreads off, but I'm not so I don't have to think about it :) Soak the whole dread in conditioner, and comb the dread out. Let me warn you that this will take a lot of time, probably 4 or 5 times longer than it took you to put them in, but if you love your hair, it's completely worth it. Some people will say that you can't do this, but you can, I know a person who did this, and I helped them take some of them out. I didn't stay the whole time, but I know when I came back the next day, they were still working on taking them out.

4. And if you have chosen the silky dread method all you have to do is take out the extensions.

It depends on which method you use.
Backcombing
You will loose about 20%-30% of your length when you dread your hair, you will loose more if you make the dreads really big or if you backcomb large amounts of hair at a time and you will loose less length if you make smaller dreds and backcomb a little bit of hair at a time.

Twist and Rip
You could loose, 50% of your length or 30%, it could go either way, your hair chooses, how it wants to knot

Neglect
You could loose, 50% of your length or 30%, it could go either way, your hair chooses, how it wants to knot

Dread Perm
You shouldn't loose much length at all, but you could loose a lot, because a lot of your hair could break off.

Twisting
You will barely loose any length, maybe 20% at most.

Comb rubbing
Well you don't have much length to start with; you won't loose enough to notice.

Dread Braiding
You will probably only loose about 10% of your length, because braids do not take much length once they are in and the hair won't have much room to move and shorten.

Silky Dreads
You won't loose any length; these are just temporary dreads. When you are tired of them just take the extensions out.

Industrial Dreads
It depends on what method you use first to make your dreads. Industrial dreads are just dreads with wire in them so they are flexible

Loomed Dreads
You will not loose any length with loomed dreads because they are temporary. Loomed dreads are dreaded hair extensions added to your hair.

Twist & Pin

You will loose 10%-20% of your length.

How do I dread my roots as they grow?

Use the clockwise rubbing method. Rub the dread against your scalp in a clockwise motion.

I used relaxer on my hair, can I dread it now?

Yes, actually your hair will dread easier because the hair has been damaged, so it will hold knots a lot easier. You can use any method and the dreads will lock up.