How do I keep my curls from un-curling at night?

by Elizabeth

I have natural barrel curls, which are just really big, loose curls. If I wash my hair in the morning, it stays curly throughout the day and I get lots of compliments on it.

However, then I go to sleep at night, and I wake up in the morning and my hair is matted and it's not really curly anymore. I don't know what to do! I've tried braiding it at night, putting it up in a bun above my hair, keeping it in a ponytail, etc., but it doesn't work.

Any ideas?

I typically wash my hair in the evening, but go to sleep after it's nearly completely dry.

Thanks!