Carlita, you are so very welcome!* Glad you like our site.* :)*
It's the interior of the pile that needs to heat up.* Several factors will allow that to happen that include the size of the pile, a sunny spot and enough moisture. I'm glad you're going to give it a turn and see if anything sprouts.* Some seeds can stay viable for a very long time.
I had not turned it. Just left it in a corner of my yard, pretty shady really. It should have heated up pretty well, all the same, since it IS in only a semi-enclosed, outdoors space, and has been through a couple of stinking hot Melbourne summers!
This site gives info about Pennisetum sataceum (fountain grass), a relative of Pennisetum clandestinum (kikuyu).* The bold is mine for emphasis.
I'm glad you are going to turn it and wait a bit to see if any germinates.
Fountain grass can reproduce by either fertilized or unfertilized seeds (Simpson and Bashaw 1969, Dujardin and Hanna 1989). Fountain grass is apomictic, meaning that it can reproduce asexually by producing seeds from the cells of female plants other than egg cells (Simpson and Bashaw 1969, Dujardin and Hanna 1989). Seeds may remain viable in the soil for at least seven years
(Tunison et al. 1995).
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.