While the colours of late summer are clear and deep and acquire extra intensity when the sun shines down from a high, clear September sky, the blue herbaceous border radiates a style and cool elegance which perfectly matches the season. Make use of nature's own fantastic staging, and create a pot garden or a whole bed of perennials that you can enjoy year after year.
Not just blue
While the blue colour is what frames the perennial universe, it is worth remembering that blue is not just blue. The colour can range from the most delicate shade of light blue, to a blue-violet with a warmer glow, to a deep, dark blue colour, such as that of the Campanula types. But it is entirely up to you whether your perennials should have exactly the same blue colour, or whether you wish to play upon a mix of several shades.
If you choose to combine several different types of perennials, such as Salvia and Lavandula from the blue-grey colour palette, you will also prolong your pleasure, as the flowering will typically take place in several stages. Many perennials such as Hosta and Sedum are evergreen, and thus help to maintain a fresh and lush look in the garden all summer long.
A common theme
You can also take a completely different approach and select a single culture as the foundation for a pot garden or bed, and in this way allow the colour shade to set the tone for the overall expression.
Varying heights
If it is a specific perennial that sets the agenda, you can naturally expect the plants to grow in a reasonably similar way. If, on the other hand, colour is the cornerstone in your plant composition, you should remember that plants of the same colour do not necessarily develop in the same way, and so you should also think about the heights of the plants.
Suggestions for perennial pleasures with a blue tone in the herbaceous border:
Agastachea 'Blue Fortune' og 'After Eight'
Aster
Campanula
Delphinium
Hosta
Lavandula
Salvia