Even though you cat has access to the outside world, hence, can do its business in a bush or something, it is recommend that you still have a litter box.
Some cats are more messy than other when using the litter box. Molly is one of those cats who love to dig and by that spreading the litter all over the place. I realised that her love for digging was not only limited to the litter box but also to the dust and dirt that is in nature. So I decided to make her an outdoor litter box hoping that she would prefer that one over the indoor one and by that stopping the litter madness.