Troughs are a great place to grow alpine plants away from the larger border plants.
Arrange tiny plants, perhaps around a piece of stone, to create a miniature alpine landscape with a dwarf shrub or conifer at one corner to add a sense of scale and maturity. See a video from Gardeners' World of Alan Titchmarsh replenishing the alpine troughs in his garden. Requires RealPlayer 1 Alpines need good drainage so make up a gritty planting mixture combining equal parts of grit and loam-based compost. Then fill the trough. Ensure the pots of alpines are moist before they are planted.