FYI Most grasses do bloom....almost all require pruning almost to the ground annually too. They are well worth it though.

If in planters, consider bamboo. It IS a grass, seldom ever blooms (most species are monocarpic), is more or less evergreen and there are both very cold tolerant choices as well as dwarf or lower growing types.

Vetiver grass is green, stiff standing and sterile.I suppose that means it does not flower , or its seeds do not make babies. It is normally used for erosion control. I do not know how hardy it is . I live in the south, so that is not an issue.