Blue and purple flower colours are popular choices for gardens, particularly at recent flower shows including Chelsea 2014. They can add some real impact to borders, particularly when tempered with more muted colours or background planting, such as a swathe of deep velvety blue irises standing out in a sea of green. Alternatively try using complementary colours, the lavender blue of Nepeta looks great when planted with the zingy acid green of Alchemilla mollis.

Purple and blue combinations
© Camilla Grayley

Purple alliums, Salvia verticillata ‘Purple Rain’ and Verbena bonarensis mixed in with tall, willowy grasses swaying in the wind make for a striking border combination.The more mauve purples of Verbena and the paler blues of Nepeta take on a luminescent quality at dusk, great for planting in a space for sitting out and enjoying in the evening.

Continue the colours at the front of the border with plants such as Geraniums, allowing them to start flowing over the edge of a path or lawn. There are an endless range of blues to choose from, the vibrant blue with its violet veins of Geranium ‘Rozanne’ (winner of RHS plant of the centenary at Chelsea 2013), to the violet blue of Geranium himalayense ‘Gravetye’ (flowers throughout the summer, often into autumn) to the delicate pale blue (almost grey blue) of Geranium nodosum or lilac of Geranium nodosum ‘Svelte Lilac’ or the more vibrant violet of Geranium pyrenaicum ‘Bill Wallis’.

Salvias

To keep the colour combinations going throughout the season consider planting asters, the lilac blue of Aster x frikartii ‘Mönch’ or the deep purple of Aster amellus ‘Veilchenkonigin’ mixed in with the delicate white umbels of Baltic Parsley (Cenolophium denudatum) to provide a contrast, punctuating the border with some spikes of Agastache or Salvias.