Classic Blue is Pantone’s Colour of the Year for 2020, and indigo is one of this season’s most winning shades. Although blue is one of the most sought-after colours for gardens, surprisingly, it can be one of the more difficult colours to find.
Indigo, always recognized as one of the seven colours of the spectrum, is borderline between blue and violet. A richly saturated colour, indigo has a long history of being indicative of wealth and prestige. From early Mesopotamian and Roman times to Indian and West African cultures, cloth and clothes dyed with indigo were highly prized.
The indigo plant was a source of early dyes, and with today’s renewed interest in organic dyes, indigo is making a comeback, both in interior design and fashion. It’s a colour that can be stimulating as well as calming, depending on how it is used.
In the garden world, not many annuals have a rich blue colour. Dark blue salvias, such as Salvia farinacea ‘Evolution Violet,’ could be the closest you will find. ‘Evolution Violet’ is very heat and drought tolerant and is an All-American Selections and Fleuroselect award winner. Another new, much larger salvia is an interspecific annual named S. ‘Big Blue.’ It grows 61 to 91 centimetres, is very weather tolerant, has a long bloom period and attracts hummingbirds, butterflies and other pollinators.
Vibrant purple-blue violas and pansies are the earliest and latest to flower. Matrix ‘Deep Blue Blotch’ and ‘Denim’ pansies are stunning, especially when contrasted with whites, soft primroses or pinks.
For blue flowers that are fragrant, it’s hard to beat heliotrope . The sweetly perfumed H. ‘Sachet’ has the most intense blue blooms.
Early in the season, before the summer heat sets in, deep blue lobelias, like ‘Regatta Marine Blue,’ Regatta Midnight Blue’ and ‘Regatta Sapphire,’ provide stunning hues that look great in both containers and hanging baskets.
Whether planted in the ground or in containers and baskets, all varieties and sizes of petunias are some of the longest-flowering summer annuals that can carry a rich indigo colour during the intensity of hot summer days. Blue petunias also have a soft perfume that often attracts pollinators.
In the perennial world, many varieties of lavender, like ‘Ellagance Purple,’ ‘Lavance Deep Purple’ and the new ‘Blue Spear,’ provide vivid blues.
For longer colour in the summertime, perennial salvias are certainly coming into their own, especially with the new, longer-blooming and repeat-blooming varieties . Many series are now more compact as well. The ‘Fashionista,’ ‘Bumble,’ ‘Color Spires’ and ‘Profusion’ series all contain varieties that provide strong indigo colours. Like lavender, they are all pollinator magnets.
Nepeta, too, is growing in popularity because of its new, improved longer-blooming habit. Proven Winners’ ‘Cat’s Meow’ and ‘Cat’s Pajamas’ are just two of these exciting must-have varieties.
From deep blue geraniums, Siberian iris and late-blooming asters to rich lupins and lovely delphiniums, they all add a seasonal punch of indigo in our gardens.
Whether it’s the colour of the year or not, indigo is always an inspired choice to add interest to our gardens.