When we moved into our house, there were a number of bushes planted in various places by the builders. We pulled a few out because wanted to put other things there. Another one died on its own which was just fine with us.
But the two bushes next to our back porch we actually liked quite a bit. In a few years when they're larger, they'll provide a nice bit of visual screening to the porch.
But this spring, when things warmed up, they weren't growing very well. On a hunch, Steph cut a piece of PVC to the right length and used it as a prototype stake, to see if holding the bushes upright would help them grow. More or less at random, she picked the left bush.
Over the next few weeks, we started to notice that bush was growing better than the other. It must be the stake helping it to stand up straight, we thought. So we bought proper garden stakes and staked both bushes in.
They both continued to grow, but the right one stayed noticeably smaller than the left one.
This seemed like a bit of a puzzle, at least to me. Was the stake not as effective as we had thought? What else could account for the left bush continuing to grow faster, despite getting equal water, shade, physical support, and so on?
One night, I took the dog out to use the bathroom, which is one of the functions of the mulch patch where these bushes sit. Like he'd done a hundred times before, he hopped off the porch, lifted a leg, and started peeing. On the left bush.
Is a dog's urine enough nitrogen to jump start a bush to grow over a foot taller in the course of six months? It's certainly at least as plausible as the idea that a stake holding the bush upright had that effect.
Of course, the other possible explanation is that the extra month that the left bush had with the stake on it was enough for it to get a lead which it has maintained throughout the summer. Without re-running the experiment the other way it's impossible to know for sure.