One of the most life-changing gardening books I ever read was Colour Echoes (1994) by Pamela J. Harper. In this book, the author explored the different ways to create colour harmony and cohesion in the garden, which all were based on the idea of putting two plants together that share a common colour but have some other difference. For example, repeat the flower colour of one plant with a nearby plant that has foliage (rather than a flower) of a similar hue, as shown in the photo above. Or pair a flower of a certain colour with a similarly hued bloom with a contrasting shape. Other techniques are to match the colour of a flower's bracts, calyces or central eyes to a nearby petal or leaf, or to place a flower nearby a garden sculpture, ornament or piece of furniture of the same colour. I am still not quite sure why, but to me these colour echoes creates a very satisfying planting combination.
It occurred to me one day that maybe echoing leaf shapes using different plants with the same foliage form might possibly induce the same sense of gratification. I started playing around with a few combinations and have enjoyed the results! Strangely, some of the pairings make me chuckle when I look at them - I am not really sure why. Maybe it's because the plants involved are sometimes unlikely bedfellows - yet sharing a common leaf shape makes them look good together! As with the colour echoes, the plants need to share a leaf shape yet have some other difference, for the grouping to work. Usually this means that one plant has a different foliage colour or texture to the other, or else the size of the leaf varies between the two plants.
As I began to explore the concept more, I realised how woeful my knowledge of leaf morphology actually was! I found there are various dimensions along which leaf shape can vary: the structure (whether has a single leaf blade or multiple leaflets, which in turn can be divided into further components, and which can vary in how they are arranged on the stem); overall shape (with a huge diversity of forms ranging from needle-like, heart-shaped, finger-like, oval and spear-shaped, to palm-shaped, round, kidney-shaped and trowel-shaped, each with its own special descriptive name); edge formation (whether smooth, toothed, curly, serrated, lobed or wavy, and so on); and even whether the leaf is folded or not in some particular way. It's all rather fascinating, and has made me appreciate foliage so much more!
Sometimes a combination can be as simple as placing a plain green plant alongside its own variegated cultivar. For example, a swathe of Iris japonica in dry shade under a tree can be instantly enlivened by adding some of its white-variegated cousin, Iris japonica 'Variegata'. A similar effect in dry shade can be achieved with a mass planting of bromeliads of different types together, as illustrated at left - there are myriad different cultivars, and with their shared shape, the scene just looks so right. In these cases, the overall profile of the plant is obviously similar, adding to the effect.
Generally speaking, I tend towards using the more unusual leaf shapes for my 'echoes'. One I have enjoyed for a number of years is plain green Aspidistra elatior paired with the silvery-marked foliage of Ctenanthe setosa 'Grey Star'. Both have bold, lance-shaped leaves and though neither plant has a flower worth noting, I always love to look at this planting in a shaded, inhospitable part of my garden, as they add a lushness that belies the conditions and look so good together.
Another combination happened by chance, when I planted some scented-leaf Pelargonium plants in a hot, dry spot in my garden then later added an unknown plant, simply because there was a spare space nearby. The latter plant had lobed leaves rather similar to the pelargoniums, and smallish, pink, malva-like blooms - for a long time I thought it was an Anisodontea. I was delighted when I eventually discovered it was annual/biennial Australian native Hibiscus geranioides (ht 75 cm), the species name of which alludes to its leaves being similar to those of geraniums (close cousins to my scented-leaf Pelargonium plants)! This aspect of a plant's species name can often provide suggestions of plant combinations.
I often pair plants with leaves with a linear or strap-shaped form - combining a specimen with wider foliage (such as Phormium) with one with much thinner leaves (such as miniatureAgapanthus 'Peter Pan' or some variety of mondo grass). In fact, one entire section of my garden, which has six garden squares set within paving, each with a different variation on this theme.
I adore plants with heart-shaped leaves and have enjoyed a grouping of a silvery Brunnera 'Jack Frost', Colocasia 'Black Magic' and a silvery-green Syngonium of unknown name, even though in my ignorance I confused true heart-shaped ('cordate') - as with the Brunnera - with arrow-shaped ('sagittate') - for the other two plants, both members of the Aroid family. However, the arrow-shaped leaves look kind of heart-shaped to me! The small leaves of Viola odorata add another heart-shaped element to the bed, and that little garden area makes me smile me every time I walk past it.
Of course, we do want contrast between leaf forms in our gardens, as well as similarities, but this approach does provide a way of creating cohesion between a group of plants, rather than having a mishmash of many different shapes competing with one another. The same principle can be applied to flower forms as well, but I will leave that to another blog!
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This intriguing epiphytic plant is in bloom now.
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As one gets older, there is the need to rethink aspects of one's garden.
Painting with coleus
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Coleus can make wonderful pictures in the garden.
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Tough and undemanding plants from my parents' garden are favourites in my own.
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Earlier this year, I visited Callan Park in Sydney's inner west.