Colour in your garden

Colour is one of the most evocative and most misunderstood of the tools available for garden design. It is important to get to grips with its various attributes and nuances because, as viewers of the garden, we are instinctively affected by colour. Although philosophies, opinions and approaches to the best use of colour vary widely and our individual appreciation of it can be subjective there are a few simple guidelines that can help a gardener realise the full potential of this fundamental design principle.

The first is to consider the way the colours relate to one another; this is best done by arranging the colours of the rainbow in what is referred to as a colour wheel or pie chart. This allows the colours to be read in a clockwise direction, starting with red at twelve o'clock through to orange, yellow, green, blue, indigo and violet.

This immediately reveals colours that have a close relationship with one another and will therefore create harmony in the garden. For example, red and orange will always 'feed' off and benefit one another, as will green and blue, and indigo and violet. So, when you are designing or laying out anything – from a hanging basket to a full blown landscape – if your desired effect is one of tranquillity and harmony then allow colours that are adjacent to one another on the colour wheel to dominate. If, however, you wish to create a scheme of contrasts, excitement and visual challenges then opt for those colours that occupy opposite positions on the colour wheel, such as yellow with violet and indigo. It is worth remembering though that while such extreme contrasts can produce an exciting scheme they can also bring discord when used too extensively.

Before determining your colour palette it is worth considering the mechanism that allows colours to shine out. The sun generates rays of light that appear white but, when viewed through a prism, are seen to be a conglomeration of all the colours on the colour wheel. (This effect is most frequently seen in the form of a rainbow in the sky, which is caused by water droplets acting as a prism.) While white light is a combination of all the colours, black displays an absence of any colour. The colour of any object that we see is a result of that object being bombarded by white light and that object then reflecting certain colours. For example: a red flower is not technically red, it is just that the flower absorbs all the colours except red, which is reflected back to our eyes.

This phenomenon has two effects: the first is that the amount of white light will determine how vibrantly each individual colour shines out. Thus in areas with high sunlight levels, such as sunny herbaceous borders and prairie meadows, the colours that appear most vibrant are the reds, oranges and yellows. It follows that if you have a bright sunny spot in the garden and you are looking for maximum impact then stick to those colours. Secondly, and conversely, the blues, indigos and violets perform best in lower light levels. Therefore, for shady spots, dark corners and under-planting choose from the blue section of the spectrum. White is a combination of all the colours and is effective in both light and shady conditions.

It won’t have escaped your attention that some colours appear much more dominant than others – again it is the red, oranges and yellows that seem to grab our attention, while the blues, indigos and violets are somewhat reserved. This is due to the speed at which each individual colour travels towards the eye when it is reflected, with the reds being produced by short wave light and travelling very quickly, while the blues, being long waves, travel slowly. As a designer, understanding this principle allows infinite manipulation of a viewer's perception of the size of the space they are experiencing. If, for instance, you have a long thin garden or space and you wish to disguise its length then plant specimens displaying red, oranges and yellows at the far end of the space – they will immediately race towards you giving the impression that the garden is far shorter than it actually is. Conversely, if you wish to make a space feel larger than it actually is then employ the use of blues, indigos and violets. This may sound like very subtle manipulation but I can assure you that it can have a radical effect.

Of course, colours have huge psychological effects and almost instinctively we will feel warmed when presented with a border that is riotous in red, oranges and yellows. Scientists are unsure why this happens but there is absolutely no doubt that a gardener standing amongst red flowers will feel warmer than one standing amongst the equivalent-sized blue specimens. (One explanation is the associations we make between the warm colours and fire and flame, and the cool colours and ice and water.) Just how warm you feel will depend on the light levels, bearing in mind that hot colours need high light levels in order to perform effectively.

For an exciting and stimulating experience when walking around your garden try contrasting areas of hot colours with areas of cool colours. With colours giving rise to psychological effects and with the importance of colour themes being emphasized by many designers you may be wondering why wild landscapes and meadows are not a chaotic riot of contrasts. This is largely due to the fact that nature arms herself aplenty with green, that most valuable of all colours, and it acts as a buffer and moderator between its more energetic colleagues. Coupled to this is the fact that that our wild plants tend to produce flowers of a modest size and an abundance of foliage and you find that the green has significantly less work to do. So, as a general rule, try to avoid including too many exotic and hybrid blooms that have been specifically bred for their impressive size and intensity of colour, and remember that the more green you use in your garden the more likely it is that your colour combinations will work.

While most gardeners consider flowers to be the principle providers of colour an astute designer will also consider the role that stems, leaves, buds and fruits play. All of these can significantly influence your impression of the plant. When formulating a colour strategy for your garden it is also essential to consider the seasonal variation of these parts of the plant and the effect that will have on the overall scheme. For instance, some plants with coloured foliage may look fantastic as part of your scheme but it is worth checking that horrific clashes aren’t going to occur when it comes into flower.

If you are in any doubt as to whether certain colour combinations will work effectively then employ the tactics of Gertrude Jekyll, possibly the finest exponent of colour theory. In her later years her sight began failing requiring her to look very closely at individual blooms and stems. In doing so she observed that a flower may, for example, be white at first glance, however, when viewed close up it will display delicate hints of other colours, such as pinks, oranges and greens. These subtly indicate the other colours that will work effectively with that bloom, creating a garden of intimate and delicate colour combinations.  

From the Gardener Magazine September Issue.