Sure you can, just let it grow wild. No styling. Low ponytail or loose and free. Check out Joe from CBS/Survivor!!!
When mine was long and I was dressed male, I used the low ponytail; when dressed female, I used high or asymmetrical ponytail (or braids, pigtails, knot) usually with ribbons and bows.
And really, who gives a rat's elbow if you look like a girly boy or a boyish girl as long as YOU like it!