Why can't Sikhs wash their hair more than twice a week?

Answer 1

It is not known why Sikhs can't wash their hair more than twice a week. Sikhs are also not allowed to cut their hair.

Answer 2

The amount of times we wash our hair is not restricted to religion, in fact it's got NOTHING to do with it (directly). But the fact that we can't cut it somewhat has an impact.

So basically:

We can't cut our hair= Hair will grow very long (unless genetics effects it or something)= Hard to maintain, and it's be unhealthy to wash it everyday= Wash it about twice a week.

This is also completely up to the person, I wash it twice a week as it's not easy to take care of and I don't have the time to put all of the effort into it every day. Not everyone has the same hair length either, mine is very long (it goes to my upper thigh) but I have other Sikh friends whose hair reaches midway of their back, so it's a lot easier to take care it for them but it still isn't easy.

So yeah, it's up to the person but MOST people tend to wash it once or twice a week because long hair is hard to take care, and it is long because we can't cut it.