Performance drawing > 1000 IM mode lines

I am using shapes to generate 2D levels. I was hoping to use the IM mode lines to draw grass.

However I'm finding that there's too much of a performance hit, I want to be able to draw several thousands of them. They don't need to be dynamic - I can bake the coords of all the blades in the generation phase. However a separate game object for each blade is even worse for performance.

Is there anything I can do to speed it up? If not, can anyone recommend a better approach for drawing blades of grass?

Thanks

EDIT

Turns out separate gameObjects are actually faster than IM mode. But a polyline with the same number of points is much faster. Is there some way to get the performance of polyline with separate lines, beyond just making segments transparent?