Whilst 50 years ago these words conjured up visions of smoke-filled rooms and extremely loud, hard rock music, nowadays, in middle age, they make me think of the colour of some of my favourite flowers which are blooming at the moment!
Purple has been historically associated with royalty and power. In ancient Rome, Egypt and Persia, purple was used for imperial robes and the earliest dye, 'Tyrian purple', was extracted from tiny marine molluscs, making it rare and expensive. Perhaps this is what gives it its rich and regal air, but whatever the reason, it brings a strong note into the autumn garden. The hue varies depending on how close it is to red on the one hand or blue on the other. I use the word 'purple' to cover these variations, which probably isn't strictly correct!
The most prominent purple at the moment comes from Tibouchina species and cultivars that have burst into bloom over the past few weeks. The most common of these is the cultivar 'Alstonville' (ht 3-5 m or more), which can be grown as a large shrub, or shaped into a small tree on a single trunk. It is a wonderful sight when backlit by the autumn sun. These days, I am favouring the somewhat more compact versions of Tibouchina, such as Jazzie, even though this can get taller than the 2 m specified on the plant label, in good conditions. It blooms over a longer season, which is also a plus. Tibouchina flowers look pretty with the pale pinks of Camellia sasanqua but one of my favourite colour combinations is purple with orange or gold, and the Tibouchina looks stunning when paired with orange Canna or Dahlia, or the bird-like blooms of Strelitzia, which are having a renewed flush at the moment.
Salvia also offer some vibrant purple flowers at this time of year. Though it can sucker, I still like Amistad (ht 1.2 m), because it literally flowers all year - except when it is hard-pruned in August to rejuvenate it. I haven't had it go berserk in my garden (yet), but it needs to be watched and reined in if necessary. I grow it with silver foliage, such as Plectranthus argentatus as well as with pink Dahlia and various pink and lilac Pentas in one area of my garden; in another spot it is grown with orange and red flowers and foliage to create a more dramatic scene. The purple form of Salvia leucantha (ht shown at the start of the blog) has long-flowering and attractive spikes of plush blooms. 'Santa Barbara' is a more compact cultivar of this plant. The lovely lime-calyx cultivar of Salvia mexicana (ht ), with its blue-purple flowers shows another effective colour combination for purple: I love the contrast of the colour lime with purple as seen in the flower spikes of this autumn-flowering Salvia.
The many species and cultivars of Plectranthus have been decorating the shady parts of our gardens over the last month or so; the purple Plectranthus ecklonii (ht 1.5-2 m), which provided a stunning mass of light purple feathery blooms, is just about over, but another of my favourite species, Plectranthus ambiguus (ht 50 cm) is looking particularly gorgeous at the moment with its whiskery , violet-hued flower heads. Plectranthus are such useful plants for shade!
A slightly different hue of purple is provided by the so-called blue ginger flower (Dichorisandra thyrsiflora, ht 2 m) from Brazil, which is blooming now in the shade. The beautiful clustered flower heads are purple-blue and appear atop of ginger-like stems of leaves. It belongs to the Commelinaceae family of plants, which includes the various Tradescantia species. Tradescantia pallida 'Purpurea' (syn. Setcreasea purpurea, Tradescantia pallida 'Purple Heart') is a wonderful foliage plant with rich purple leaves that can provide colour all year round in shade or sun, and can provide a good companion to its cousin the blue ginger.
Heliotropium arborescens (ht 75cm) - sometimes called cherry pie because of its deliciously perfumed purple flowers - can bloom all year round in our benign Sydney climate, and it is a good little shrub to include in a sunny border. The cultivar 'Lord Roberts' is recommended for its richly coloured flower heads. Trim off spent flower-heads to promote continued bloom.
To provide purple flowers through winter and spring, now is the time to plant up some bowls of purple annual Viola or pansies, which will brighten up the days ahead!
Blog originally posted 11 April 2010; updated 10 April 2022
Hi, is the Lord Roberts, a commonly available plant? I love the look of it and the smell sounds divine too. Am I to understand that these plants will cope with full summer sun and its only frost that makes them unhappy? Sheryl
Lord Roberts is pretty widely available and has the best colour. There are lilac and white ones that are pretty too, plus one with golden foliage and lilac flowers. They like sun (the gold-leaf one can be grown in part shade if it is grown mainly as a foliage plant and not so much for the blooms) and they are frost sensitive. Don't ever prune in winter - wait till September. Deirdre
I have another purple flowered shrub called Thunbergia erecta cv vogellii which I have had flowering in my garden for about a year. It is a shrub and grows to about 2m tall. Margery.
Thanks, Margery. Yes, that is lovely plant. I have seen it in friends' gardens and I must take a photo of it! Deirdre
I am also a big fan of purple and Thunbergia erecta is one of my favourites. I am living in East Timor and I recently saw a rich deep purple Thunbergia erecta intertwined with a very bright yellow Allamanda. The combination was absolutely spectacular. Terry
Thanks for your comment, Terry. I am really interested in what grows where you are, as I have a friend currently living in Jakarta who is creating a garden there. I'd love to know more of what you grow. Deirdre
Thanks for the photos! Your friend's Salvia leucantha looks so stunning with the blue bench! I'm so enjoying the salvias just now. The Anthony Parkers have, as you have warned, Deirdre, taken over in some spots and I'm taking cuttings for places where they can do just that. They are at their gorgeous peak. The leucanthas and Amistads look wonderful with them, and with the scarlet of pineapple sage. All a wonderful foil for white cats' whiskers. Joy! It sounds wonderful, Jude. This is such a good time for many salvias. Deirdre
Oh yes the purples are strong in my garden. Tibuchinas not stopped blooming, waiting to prune these. There are 3 Salvias in shades of purple and the purple ginger as well. Then theres the Pentas. So yes enjoying the purples. Oh yes, I forgot the Pentas, which have some different shades of purple! So long-flowering! Deirdre
Purple flowers in the garden provide a beautiful vista - particularly salvia leucantha, plectranthus eccloniin planted near white, yellow and orange flowers. My salvia and plectranthus have been flowering for over two months. Lighter tones of purple pentas, plectranthus ambiguus and purple buddleja also provide pleasure. One purple plant I desire is the purple ginger - such a gorgeous hue, so far, I have had no luck in acquiring it. Your garden must look so gorgeous, Margaret! Deirdre
I just purchased some Tibouchina Groovy Baby plants to give me more flowers in autumn as I had to take out the other tibouchinas as they grew too big. Here's hoping Groovy Baby will stay at 45cm as the label says!! Hope that works out! Certainly, 'Jazzie' gets bigger than anticipated but I still love it! Deirdre
November climbers
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Hydrangea buddies
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Good companions for Hydrangea shrubs
Fuchsia time
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Self-sown surprises in spring
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It's fun to discover new plants in the garden.
Silver in the shade
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Some beautiful silver-foliage plants thrive in shade.