I was always taught to use a 1:5 ratio of urine and water. When I used to garden quite a bit (before the deer got too bad), I would pee in a watering can, fill it with water and go. did this as much as I wanted and never had negative effects. The human smell helped keep critters away to an extent.Does this mean I can piss on my acacias just like my cacti? - ah, no! Phosphate! Somewhere you said acacias are not so keen on higher phosphate?