Time to Reconsider Coleus

Guest Post by Robert Wilson

The Case for Native Australian Species in Garden Design.

Love them or hate them, whether they are Coleus or Plectranthus, whether they feel nostalgic or a little bit "Granny garden", it’s time to take a fresh look at this diverse and under-appreciated genus.

Coleus has a broad distribution across Tropical and Sub-tropical regions of the world, but a special mention should be made for the charm, toughness, tactility and interest of our little native species (more on those later).

Let’s start with the familiar face: Coleus scutellarioides, the Painted Nettle. Spread throughout South East Asia and parts of Northern Australia, this is the garden variety we love (or don’t). It’s loud, it’s loveable(!) and when you look for it, it’s everywhere! Dayglo colours, wild leaf patterns, velvet textures, exotic leaf shapes. There is a cultivar to suit every palette. They are fun to collect, easy to propagate, accessible on any budget, and forgiving under most conditions. Garish or kitsch? Or A bold, herbaceous infill plant that emphasizes tropical plants with almost year round colour and interest! A winner in Brisbane, tolerates a range of conditions but for best colour, plant in dappled light and prevent flowering by dead-heading regularly. A minor few display good foliage colour in full sun (one of these is pictured). They can be standardized, pruned hard, plaited, heeled and generally forced into horticultural submission. For cheap, impactful, full, fast growing, tolerant, tough and vibrant bedding displays; get a hold of some “Painted Nettle” today!

I want to make a bigger case, one that speaks further to scent, texture, and mood in our gardens.

Australia’s native Coleus/Plectranthus species are not only beautiful: they’re powerfully sensory, and critically underused. Unlike their bright exotic cousins, native Coleus don’t shout. They enhance the pomp and circumstance of their big brothers and sisters in the garden. They support bold colour (or enhance earthen tones), radiate scent, and invite touch. They offer subtle leaf shapes, aromatic foliage, ease of maintenance, and floral displays that surprise in the dappled light. These aren’t feature plants; they’re the glue in a planting design. A skilfully selected and beautifully designed frame will enhance any artwork. They deserve far more love.

Let’s explore a few that bring scent, tone, and tactility into the spotlight:

Coleus argentatus (Silver Coleus)

This soft, silvery shrub shimmers in the shade. The foliage has a suede-like feel that begs to be touched, and its tall spikes of white, mauve, or soft blue flowers make it a beautiful alternative to lavender, especially in subtropical beds where lavender may fail. It’s cooling, calming, and quietly luminous. With its bright foliage and reliability in lower light conditions- perfect for brightening a shady or dull corner of the garden!

Coleus graveolens (Bush Basil)

A plant of surprising depth. Thick, textured leaves with a bright lime green tone and a strong, resinous aroma, somewhere between basil, mint, and native herbs. The foliage feels almost succulent under the fingers, while its purple-blue flowers rise up on soft stems. It brings density, texture, and fragrance to native garden designs. Large, intricately veined leaves provide the perfect foil to bold native wildflowers such as Grevillea or Hibiscus.

Plectranthus nitidus EN (Nightcap Plectranthus)

A small, endangered rainforest species that absolutely glows in low light. Glossy green leaves with maroon undersides and stems, a crisply toothed margin, and elegant leaf venation make it one of the most beautiful bedding plants for shady areas. Its flowers are like tiny chandeliers, twinkling purple and white across the understory. Want to see it? Gold Coast Regional Botanic Gardens has it planted in sweeps and mounds beneath rainforest trees; an absolute masterclass in subtle beauty.

Coleus bellus Rare (Coleus “Mount Carbine”)

Tall, tactile, and bursting with lemon-sherbet scent. Its velvety leaves carry a rich citrus aroma that releases as you brush past. This is a plant for people who understand gardens as spaces to feel as well as look. It makes a fantastic sensory border, cut it back hard, enjoy the soft flushes of new growth, and let it do the work lambs ears can’t do in the tropics and sub-tropics. Or let it standardise for a quivering display of electric green texture in the back of a bed. While not a showy flowerer, C. bellus sports a delightful and reliable sky blue flower.

Coleus alloplectus EN (Slenderleaf Hullwort)

This is my favourite; tough, bronzed, and full of personality. Its new growth bursts in tones of gold, copper and bronze, it sets the stage for bold spikes of purple flowers. It thrives under pressure, responds beautifully to pruning, and pairs exquisitely with native garden design tones: olive, parchment, drab, stone, silver and dun. It’s a complementary gem with year-round interest.

The Native Garden: A Balanced Approach

With the ongoing discussions about some exotic species becoming problematic in parts of Australia, I felt it was time to reveal that while I love native plants, I also have a deep appreciation for many exotic species and believe they can coexist harmoniously.

The Native Plant Misconception

It’s important to recognise that just because a plant is native doesn’t mean it won’t become a weed. Take the Cootamundra Wattle (Acacia baileyana) as an example. This beautiful, fast-growing acacia is naturally restricted to the South Western Slopes of New South Wales. When planted in higher rainfall areas, it can aggressively invade surrounding bushland, self-seed, and become a nuisance. 

Another misconception about native plants is that they require little to no maintenance. A native garden, like any other garden, requires effort. This includes:

• Soil Cultivation: Regularly improving soil with compost and organic mulch.

• Fertilising: Using products like Organic Link at the start of each season and supplementing with regular liquid fertilising.

• Maintenance: Trimming and replacing plants as weather conditions change.

Responsibility

People must start to take responsibility for our plants and gardens. For instance, Syngoniums, a popular houseplant, are classified as weeds. Do we stop cultivating this plant, or do we educate and ensure responsible care and correct disposal, if needed? As a professional horticulturalist, I explain the potential pitfalls and dangers of allowing such plants into the wild. I expect their new owners to trim and care for them to prevent them from becoming out of control. I expect people to allow themselves to be educated and take on that advice. You cannot buy a climber and then get upset when it climbs.

Choosing the Right Plants

• Reputable Sources: I only purchase plants from reputable sellers. For example, seed-grown vinca (which I do not sell) can be a weed, but with modern horticultural advancements, sterilised vinca won’t usually last longer than 6-12 months (this is what I stock).

• Local Availability: Many Southeast Queensland natives are not commercially available because they are hard to cultivate in large numbers or aren’t as visually appealing as their Western Australian counterparts. Thus, a native garden in Ipswich might consist of 20 Western Australian and South Australian natives and only a couple of Southeast Queensland natives.

Genetic Dilution in Local Australian Plants

Genetic dilution refers to the weakening or loss of genetic diversity in local native plant populations due to cross-breeding with introduced species from other areas or non-native species. This can lead to several ecological and evolutionary problems, including reduced adaptability to local conditions and the loss of unique genetic traits.

An example of this happening is with the Australian native Corymbia torelliana, commonly known as Cadaghi. It is native to northern Queensland, Australia, and has been widely planted outside its native range due to its fast growth, aesthetic appeal, and usefulness in timber production.

Corymbia torelliana can hybridise with closely related species, such as other Corymbia species and some Eucalyptus species. When this occurs, the genetic material of Corymbia torelliana mixes with that of the native species, resulting in hybrid offspring. These hybrid offspring may exhibit reduced fitness compared to pure native species, including traits such as lower resistance to local pests and diseases, or reduced adaptability to local soil and climate conditions.

The genetic dilution of native species can also lead to a reduction in biodiversity, potentially disrupting ecosystem functions such as nutrient cycling, water regulation, and habitat and food provision for other species.

Corymbia torelliana produces a large amount of pollen, which can be dispersed over long distances by wind or pollinators like bees. This increases the likelihood of cross-pollination with native species over longer distances. Just one tree can affect a very large area.

The Role of Exotic Plants

Native and European plants can be used together. Many fruit trees and vegetables aren't native, but that doesn't mean we should stop growing them. Many herbs, like garden mint, and comfrey, can become weeds, yet we don’t stop cultivating them. Instead, we focus on education and responsibility.

I have personally found Camellia sasanqua flowers and bacopa (both exotic) are a preferred flower for my native bees.  Lemon Balm (Melissa officinalis) was traditionally used by the ancient bee keepers. They used to rub the crushed leaves on the beehives to encourage the domesticated bees to return to their hives. They also believed that the lemon balm would also bring new bees to the hive.

Creating a garden, whether it be native or a combination, requires thoughtful planning and effort, but the results are worth it. By understanding the specific needs of our environment and taking responsibility for our plant choices, we can create beautiful, sustainable gardens that celebrate both native and exotic species. Let’s continue to educate ourselves and others while embracing the diversity that makes our gardens thrive.

Native Daisy

Brachyscome multifida is endemic to Australia and a brilliant free flowering hardy ground cover daisy.

This cute little daisy has fine feathery foliage and can grow to about 50cm diameter and about 40cm high.

It prefers full sun in good quality free draining soil. The flowers usually appear from mid winter until summer but they can spot flower continuously if conditions are right. The flowers are usually shades of pinks and purples.

They don’t mind the cold or a little bit of dry but do need a top up water.

Fertilise then seasonally with a good quality complete organic fertiliser like Organic Link. They also appreciate a liquid fertilise with Triple Boost to keep them powering on.

I think these guys make great fillers in gardens and work like a living mulch. I also have seen them tumbling out of urns and as hanging basket specimens for full sun areas.

I think these guys are really cute and would work well in a cottage or formal landscape. Sometimes we all need a daisy in our lives.