This is a super blue grass. Grow outside..as if kept inside it WILL get mildew. Any small amounts of mildew on plants from here WILL disappear soon after planting out.
Elymus magellanicus is a great architectural perennial grass with intense blue swords and straw-yellow flowering spikes carried through the summer. Fully hardy, grow in any moderately fertile, moist, but well-drained soil in full sun.