After transplanting, it will take a few years to get the rhizomes back to a large enough size to support large topgrowth.

Here in Texas, depending on the variety, it could take 5 years, maybe more, to get back to that large size.

Fertilizing and making sure it has enough water during dry spells will help speed this up.

Kt

I was going to dig up some bamboo this spring and transplant it. Can I dig up roots and cut stem off at about 2 feet high? Won't the bamboo just spread by root matter? I want to do this so I can transport it easier.

Yes, you can do it that way. The larger the rootball and the more topgrowth you leave, the better chance of survival.

I've done that before and cut the culm off below any nodes with stems. It was the following year before it put up new shoots, though.

Kt