From what I've read, these can be slower than other species of Phyllostachys to begin to spread. If your weather has been dry in recent years, it my be drought related. Have you been feeding in the growing season? PS. They may be spreading underground at this point.

12 inch high little "pieces" ? Did you mean shoots? Or tiny tiny culms? New plants start out with tiny shoots/culms then they get larger and larger in diameter.

I hope you didn't remove the 2 foot shoots??? The plant can't get bigger until it grows underground, and gets more shoots making food from sunlight on leaves..

Moso usually does most of it's growth underground the first five years so patience is a virtue here. I have a grove that is eight years old and last year started looking really good for the first time, then it started shooting on March 3rd and we got another frost, of course before the month was up and it killed 3/4 of those majestic culms. I was heartsick!

I happen to live in Anderson, SC and was able to dig a 2 inch diameter culm with 4 foot wide root ball. The following year this transplant put up a 3 inch culm. I think a lot depends on how much of the root ball you get, amount of rain per year, and how much you feed the plant. Planting near a creek seems to help a little bit if the rainfall has been plentiful. Mike in Marietta, SC has a huge grove of moso but I have not seen him posting much on here lately.

-Evan

My division was about a 16 inch rootball, so it wasn't really very big. It
is still alive but not doint much. Hopefully someday it will become
something.

I have seen pictures if Mike's bamboo very impressive.