I have found that pet shops can be great places to find interesting garden plants. I’m referring to the plants being sold in the aquarium section – for these plants are not necessary water plants at all, and in fact many will gradually deteriorate if grown continuously submerged. While searching through some aquariums yesterday, my score was Iresine diffusa ‘Lindenii’, a plant for which I have been searching quite some time.
So easily grown from cuttings, Iresine, blood leaf, beetroot plant or chicken gizzard, are plants you are given by friends, are found at the local church fair or are simply grown from donated cuttings in a glass of water.
Tough, hardy and colourful, these showy plants with their brilliant leaves and soft stems can be a great addition to a planting. They will grow in full sun, semi-shade or shade, although the brightest colours are generally obtained in stronger light.
Despite their colourful leaves, the flowers themselves are disappointing and fairly insignificant – in fact they don’t appear appropriate for these plants at all. The grass-like panicles of flowers emerge in late summer or autumn, as the days get shorter. All clones in cultivation appear to be sterile, so there is no chance that this plant could ever become a weed.
The plants we grow are all cultivars of Iresine diffusa (syn Iresine herbstii), a species with a very broad distribution, being native to the south-eastern states of the USA, Mexico, and almost all countries in Central America, the Caribbean and South America. The wild plant is quite unassuming with narrow green leaves and an upright growth habit, and you would easily overlook it. The plants we grow are selected cultivars that were described in the mid 1800s from plants introduced to England and France and grown in the conservatories and stove houses (heated greenhouses) as exotic treasures.
Iresines were most popularly grown during Victorian times, when they were used for colourful summer bedding arrangements. The plant lost popularity as the rage for these installations declined. However the fashion for colourful tropical looking plants gained momentum once again in the 1950s and 60s with post war opulence. You will spot Iresine in photos of the spectacular abstract 1960s plantings of Brazilian landscape architect Roberto Burle Marx. In the early 21st Century, exotic colourful foliage again became popular, thanks to the likes of Christopher Lloyd and other notable gardeners and Iresine reappeared appeared in private and public gardens.
Iresine diffusa ‘Brilliantissima’ is probably the most popular cultivar. It has heart shaped leaves and a slightly upright growth habit. The stems and petioles (leaf stems) are a brilliant pink and the leaves vary from brilliant pinky-red to a browny, beetroot colour with pink veins. Like all Iresines, leaf colouring can vary immensely depending on light, with brightest colour generally in full sun.
Iresine diffusa ‘Formosana’ is very similar in growth to ‘Brilliantissima’, but has green and yellow leaves. In full sun they may appear almost totally yellow, while in shade they are green with yellow veining. A feature of this plant is the brilliant pink stems and petioles.
Iresine diffusa ‘Verschaffeltii’ resembles ‘Brilliantissima’, but has indented, kidney shaped leaves and a slightly more rambling growth habit and open growth, which gives it a different character when seen in the garden. Illustrations of this cultivar were first published in Flore des Serres et des Jardins de l’Europe Volume 15, 1845.
Iresine diffusa ‘Aureo-reticulata’ is identical to ‘Vershaffeltii’, but has yellow and green leaves, contrasting with the striking pink stems and petioles. Unlike the other yellow cultivar ‘Formosana’, it is less stable and many leaves have reddish patches or entirely red leaves. The plant frequently sports back to ‘Vershaffeltii’, which is a likely parent. Illustrations of this cultivar were first published in The Floral Magazine, 1867.
These four cultivars generally grow to 500mm (22 inches) to 1 metre (3 feet) high by 500mm (22 inches) to 1.5m (4 and a half feet) wide. However over time, and in good conditions, they can spread across the ground as groundcovers, rooting at the nodes and forming a mass a few metres (yards) wide. If they have a chance, the plants can also sprawl up against other shrubs and climb to almost two metres (6 feet) high, intertwining and creating a mixed arrangement of colourful leaves. However they respond well to pruning – and the soft stems are easy to prune and readily compost.
My recent prize – the Iresine diffusa ‘Lindenii’ – has upright growth and narrow, upright leaves. This growth habit is very similar to the wild, green-leafed ancestor. The leaves are beetroot coloured with small pinkish veins towards the centre of the leaf. I have never seen it growing outside in Australia, but this plant is mentioned in a number of early Australian books. It is an example of how readily plants can fall from fashion. The plant is still grown overseas, and a good friend of mine in Auckland, New Zealand has an impressive planting by the front door – a constant reminder to me to keep hunting for it. Now that I finally have a plant I will have to work out where I will locate it for best effect. Illustrations of this cultivar were first published in Flore des Serres et des Jardins de l’Europe Volume 17, 1845.
Another Iresine has recently become available in Australia. I found my plant one lunch time, in the garden section of K-Mart. This small leaved cultivar is marketed as Iresine ‘Neon Pink’. It has small leaves and the typical bronze and pinkish-red colouring – a miniature version of ‘Vershaffeltii’. The plants I saw in the store were a little straggly and didn’t have much colour. At first I couldn’t decide what they were. Don’t let this put you off, should you see the plant. Now that my plant is in the garden, the leaves are gradually suffusing with colour. Iresine ‘Neon Pink’ has quickly grown into a dense bush of small colourful leaves.
If you visit the tropical garden in the Royal Sydney Botanic Gardens or the Auckland Domain Winter Gardens, you will see plantings of yet another Iresine cultivar, Iresine diffusa ‘Wallisii’. This plant has small, twisted, kidney-shaped leaves, which are almost black above and wine in colour beneath. The plant has a sparse and very upright growth habit. If you are lucky, you may find a plant for sale at one of my favourite haunts, the Royal Sydney Botanic Gardens Friends Nursery – just follow the signs (it’s tucked in behind the Cactus and Succulent garden).
Once established, Iresine cultivars are reasonably drought tolerant for herbaceous plants. However with constant moisture, plants thrive and grow more rapidly. It has been very dry for over a year in Brisbane, and my plants may not be growing vigorously, but they still look good despite limited water. It would be great to see this hardy plant being more widely used in our public landscapes. As we know, people respond positively to colour in the landscape.
Iresine is also fairly tolerant when it comes to soil. They prefer free draining, moist soils for best growth, however I have seen them growing in sand, puggy clay and in low-lying areas that flood. To get the best from your plants, prepare the soil incorporating organic matter and mulch. Avoid using high nitrogen fertilisers, which may encourage soft growth and a dilution in foliage colour.
Iresines thrive in frost-free warm temperate, subtropical and tropical climates. However, as English, European and North American gardeners found over a century ago, these are easy plants to incorporate for summer colour. As the weather cools, cuttings can be taken or plants can be lifted and brought inside or under glass during the cooler months.
They may be common and readily propagated, but don’t look past the many Iresine cultivars if you are after hardy, low maintenance plant that pack a punch with foliage colour.
Finally a postscript – a popular bronze leaved groundcover, Cyathula prostata, is being sold in Australia and the USA as Iresine ‘Purple Lady’. An Iresine it certainly is not. You just need to look at the flower spike to note the difference. It would be great if the nurseries involved could correct their labels. Many people try to locate Cyathula after seeing it used so well in the gardens of Bali, Singapore, Malaysia or Thailand. This confusion impacts on plant sales at garden centres, as customers are unable to find the plants they read about and for which they are searching.