Here's what you might expect from your yellow groove divisions in another year. It turns into a grove pretty fast, but compared to other phyllostachys, it have very light foliage and doesn't get buried by the snow at all. This makes it a bit more susceptible to leaf burn, but we haven't have very cold temperatures yet. This one was planted in June of 2009. Based on yellow groove I've seen in the area, I don't think this species should get any larger than 1.5 inches by 25ft, but I'll do some selective thinning to hopefully get mine bigger.

Here's how they look like rising during the spring of this year. It didn't start out with that many culms as shown here, but it put out over 30 shoots before I thinned them out. I also doubt it will shoot as well as it did since rhizomes didn't seem to spread much this year.

If you have a pond, you should probably consider growing phyllostachys atrovaginata or any other bamboo with air channels in their rhizomes right next to it since it is supposed to do especially well next to water.