Is there a way to fix a reed that's split down the side?
Not neccessarily all the way down, but more just at the top to middle - making it hard to play but still playable...

or should I just throw it out and be more careful?

I think that you can't fix a cracked oboe reed in any case.

Plus, if it's hard to play, why play it when you can get another one?

I think he means a split reed.

Just soak it, play on it for a few minutes... (Scales, long tones.)...Soak it again, and it should be fine...

<Added>

he/she.

Not meaning to be sexist here!

yeah, if he/she means that it's split, that would be what you'd do.

(she :P)

Yeah,'kay, thanks...
problem is that over here I can't get reeds very easily, there's one music store that sells them and they're way expensive...

Cracked Reed = bad day.

Yeah, just soak it, sometimes it actually "fuses".

you use reed until they crack and then get a new one. you cant fix them, only replace them.