What makes the colours in this photo of the Glasshouse border at RHS Wisley look so great together? The glowing yellow and orange heleniums practically hum with energy against the rich purple and deep blue of the Eupatorium and Veronicastrum. The reason for this effect is that orange and blue are complementary colours, as are yellow and purple. What’s a complementary colour, you ask? Well, it’s all to do with the colour wheel.
The colour wheel is a nifty tool beloved of garden designers. Essentially, it’s a way of arranging colours like spokes on a wheel in a way that demonstrates their relationship to each other. Colour wheels have been used in the study of light and colour theory for centuries – in fact the first one was developed by Isaac Newton in 1666. They’re available in art shops, and there are plenty of examples online. For gardeners and garden designers, a colour wheel makes choosing great plant combinations easy.
To start using a colour wheel, you simply need to know the difference between harmonising and complementary colours. Here’s a basic guide:
Complementary colours
Complementary colours are placed opposite each other on the colour wheel. Combining two complementary colours actually makes each colour look brighter, creating a vibrant, highly stimulating atmosphere. It’s great for making a dramatic impact in a big space, and it’s also very effective on a smaller scale. For example, if you’re planting pots for winter colour, choosing bright orange violas in a blue pot creates a combination that will look stunning even on the dullest day.
Shocking pink cyclamens combined with the lime-green leaves of Heuchera ‘Key Lime Pie’ are another great example of how complementary colours can bring out the best in each other.
Harmonising colours
Complementary colours are ideal for high-impact planting, but if you want to create a more tranquil, calming environment, choose harmonising colours for your planting. Harmonising coloursare located next to each other on the colour wheel. This gorgeous combination of blue, purple and pink flowers in the Hampton Court Palace rose garden shows harmonising colours working together beautifully.
A handy tip to keep a harmonising colour scheme from feeling bland is to add in a single complementary colour as an accent. So for example, if your palette is predominantly pinks and violets, a scattering of acid-green euphorbias will punctuate it without detracting from the overall atmosphere.
Using the colour wheel is a good way to develop your confidence in putting together planting combinations in your own garden. But remember, it all comes down to personal preference in the end, so if you like the way something looks, don’t be afraid to break the rules – it’s your planting scheme, after all!