You are required to wash flowing hair on a standard basis therefore the dirt which isn't caught for the head due to wind blowing is washed away.
If you have a delicate daily shampoo at home, you can actually use it to wash your mane on a daily basis without any adverse the consequences. https://images.google.is/url?q=http://www.betsyrosspatterns.com/10-signs-youve-found-a-good-hair-salon-for-your-needs/