For one handed - pretty good. I know what you mean, an assistant could often help us. I have looked at quite a few National Geo videos, and the photographers often have 2 or 3 people assisting them.
I agree completely. This was one of those times the photographer could have used an assistant (or maybe just a garden stake). I was shooting with one hand while using the other to hold a branch. That couldn't have been helpful.
We just had a torrential thunderstorm that fortuitously came before the tree peony's blossoms opened fully. They get clobbered almost every year, so we know to enjoy them while we can.