Ornamental Grasses

I have a few grasses that I am trying this year from seed. What is your recommendation of # of seeds per cell (2") for a nice clump?

Laguras ovatus Hare's Tail
Isolepis Live Wire I. cernua
Millet Purple Millet
Panicum Frosted Explosion, P. elegans Panic Grass
Stipa Ponytails, Nassella tenuissima

The only one that I have started is the stipa ponytails. I usually put two to three seeds in each cell. I remember that they seemed to stay a couple of blades for the longest time. Once it began to warm up outside, they finally became fuller. Each seed did become a nice size clump

I have Stipa Ponytails, Nassella Tenuissima in my yard and a note to the wise they self seed. I found 2 pony tails coming up this spring, but I like them so it is ok for now. However when they get to big I will have to moves them.

The stipa ponytails did not self seed in my garden. They didn't overwinter.