Posted: 14/05/2015 at 06:35
The RHS says the following:
"A vigorous spreading grass with blue-green foliage, this grows almost anywhere and is particularly valuable for shady areas under trees or in a semi-wild garden. Use it as tall, weed-smothering ground cover, or blend it with other vigorous plants such as self-seeding annuals and perennials for a low-maintenance, cottage garden-style border. It can be invasive, so restrict its spread in more formal surroundings, by treating it like mint and grow in a large pot sunk almost to its rim in the ground. Tall, pinkish flower-heads are produced in summer."
Keeping it in a pot sounds like good advice to me!