How does washing help your hair grow?

[Chanteuse]

I know that washing your hair often is a key factor in getting a lot of growth. What I don't know is what about washing your hair makes it grow? Is it the fact that the water is stimulating your scalp or is it just the fact that your hair can grow better through a clean scalp?
I was reading another post by someone who said they use an herbal scalp cleanser sometimes and I'm wondering if that has the same benefits of physically washing your hair or if your hair/scalp needs the water to thrive - or a combination of both.

 

[Purtygurly]

Having a clean, unclogged scalp promotes growth.

Washing also moisturizes hair... well really it's mostly the conditioning done after washing that moisturizes the hair. Moisturized hair helps you to retain length.

Also when hair has product build up on it, it gets dry, which leads to breakage.

 

[DDHair]

Also water helps pores to open, so when you apply products while pores are open, the product is absorbed more easily. I know that with photosynthesis and plants and watering them works, my ivy grew so long from the proper watering. I kind of equate that to humans drinking water and proper washing.

 

[Poohbear]

interesting... im glad i found this thread!