I can normally go up to three days without washing but if you want to go longer you can use a dry shampoo or just put it in a ponytail. You'll want to wash again when the roots look greasy or you just know it doesn't look or feel right. It all depends on how oily your hair gets.

Hair type:3a
Cleanser: devacurl or devacare nopoo, dc lowpoo
Ro: DC onecon., KCKT
LI: DC onecon., KCKT, CJ cccl
Stylers: CJ cccl, FSG, Cj ciab, DC angel
Oils: coconut oil, apricot kernel, grapeseed