These bulbs thrive in full sun or partial shade and any well-drained soil. Muscari armeniacum bulbs planted in a prior year often produce tufts of grasslike foliage in late summer or early fall, which has the benefit of reminding you where they are when you are planting additional bulbs. They will bloom on schedule the following spring.
Note: Do not be concerned if you see blue mold on your muscari bulbs. Go ahead and plant them. The mold will not affect their performance.