What to do with my horses mane for a show?

I know you are supposed to braid, but I totally screwed her mane up, half of it is pretty much unbraidable, and the other half is but kind of uneven so it will be tough. How short do I have to make her mane so I don't need braids? I've looked online and I can't find anything about it. I'm going to a state fair show (4-H / FFA project stuff) and then a USEA event. Should we completely roach it?