You can't just dig up a culm ("stalk"). You have to dig up a root ball with it...the larger the better. What size culms are you talking about?

The culms are on average around 1.5", I was going to dig them up as a root ball, now how large does the ball need to be.

For that large of culm, the larger the better...at least basketball size would be good and no more than 3 culms per root ball. Also, try to extract the root ball with the dirt still on the roots as it will do much better than a bare-rooted clump. Be aware that you will need something like a root pruning saw to cut through the roots all around the outer circumference of the root ball, and something like a demolition bar to pry the root ball out of the ground (so there is less chance of breaking your shovel).