Great, lol, lets all go squeeze out our tampons over a jar and offer it as sacrifice to the Garden God
Ugh, I am so not usually that gross.
Or you could just use a mooncup and empty into a jar to save for your plants. 
Oh yeah, I keep seeing adverts for those things all over the place. What the hell are they exactly? Some kind of little cup that sits where a tampon would? I still use towels anyway so doubt they would be any use to me. I wouldn't trust tampons due to the risk of TSS.
Here is the Mooncup's website and you can see pictures there if you like, Graelwyn:
http://www.mooncup.co.uk/You put it in like a tampon, but it catches the fluid rather than absorbing it like a tampon. I read on their website that the Mooncup is not associated with Toxic Shock Syndrome because it is not an absorbent product. I normally prefer pads to tampons as well, except in certain circumstances like swimming because tampons make my menstrual cramps worse.