Larry,
Around winter time a lot of the discount stores put their lawn irrigation pipe on clearance. Its black in color about 1" in diameter and comes in a 20' roll.
You unroll it and stick the little pop-up sprinklers into it.
I buy a couple of rolls and cut them into 2 1/2 to 3 feet pieces and cement them into the disposal nursery pots. When you are finished it really makes a good looking stump.