Ashley Graham leaves at least three days between shampooing. (Picture: Reuters)

Ashley Graham hates washing her hair and revealed she tries to leave at least three days between shampooing her tresses.

The 31-year-old model - who is expecting her first child with husband Justin Ervin - has revealed her eight-step skincare ritual, which starts with her tying her brunette locks back to stop any product getting in to it because she tries to leave at least three days between shampooing her tresses.

She said: "I have a combination skin type, it's a little bit oily, a little bit dry. I get a little dry around my nose and sometimes dry on my chin and I would say my cheeks are combination 100 percent. If it's summer time we're oily, if it's the winter time we're dry so I'm always changing it up.

Ashley has combination skin. (Photo: Instagram)

"I hate washing my hair so if I can leave my hair for two to three days, I'm going to do it. When I'm sleeping I don't put my hair up because I already have so much volume on top of my head then I look like a cone head, so I always go back with it. It's just something I've learnt about myself."