General advice is to plant Foxgloves at the back of the border because of their height - up to 5ft or more. But with great beefy Cardoons behind them they can come forward. In Spring, the Cardoon leaves muscle in first, at such a speed you can almost watch them grow. The Foxglove fireworks then go off in June, their ascending tubular bells showing well against the silver-grey Cardoon foliage. Last the Cardoons thrust out their purple-flamed cannon ball heads in August. You can almost hear the bangs and smell the gunpowder. There's also a sense of something primal, or prehistoric, going on. Not for gardeners of a nervous disposition.