Originally posted by ubiquitous
There is another issue that those of us with outdoor (or indoor/outdoor) cats prefer to overlook. Outdoor cats tend to “take care of business” in the neighbor’s yards and gardens. I don’t expect any new or startling solution to my dilemma. Perhaps just some sympathy.
Two solutions to outside toileting.

Provide a litter tray for him, we have several for our cats inside.

For your case this could be in a shed, garage or out building

OR

Dig an outside toilet for him. Dig a hole in the ground, metre square and a couple metres deep filled with safe sand. He will use this area to toilet in. Just turn over with a spade frequently.