Justicia betonica, background planting

I have always loved plants that have flowers on tall spires - a legacy of my cottage gardening years when I was so influenced by traditional English gardens, with their soaring hollyhocks, foxgloves and delphiniums. These gave such a dreamy, ethereal look to gardens and I yearned to create a similar garden in suburban Sydney. I discovered many of the cottagey stalwarts didn't do well here, but I found some substitutes that did the job. Most of these bloom in late spring, and I have written about them here. However, surveying my late summer garden, I found there are lots of flowery spires on warm-climate plants that thrive in Sydney, which are bringing joy at this time of year!

Salvia Mysty, a compact version of Mystic Spires

Salvia Mysty, a compact version of Mystic Spires

Salvias were mentioned in the late spring blog on spires, and in late summer, many are still offering welcome flowers. Perhaps the most indefatigable is Salvia 'Indigo Spires' (ht 1.5 m), with its long, deep blue inflorescences. If lightly trimmed back on a regular basis, it will bloom from October to May. 'Mystic Spires' is a related plant that is said to be shorter, but it is really not much different in size, in my experience. Last year, I obtained what was stated to be a miniature form of 'Mystic Spires' called 'Mysty' (pictured above), and so far, it has lived up to that claim, growing only about 30 cm tall. It is rather cute for the front of a border. Lots of other Salvia cultivars are in bloom now, offering spires galore: hot pink 'Joan', lavender-blue and white 'Phyllis Fancy', plum-hued 'Desley' and rich purple 'Amistad' to name just a few.

Lepechinia salviae

Lepechinia salviae

A shrubby plant sometimes mistaken for a Salvia is also coming into flower now: Lepechinia salviae (ht 1.5 m). It has large, grey-green textured leaves shaped like arrowheads; they have a sharp medicinal - though not unpleasant - scent. From late February to May it sends up long spires of burgundy flowers, held in dark calyces on deep pinkish stems. It is a tough plant that can tolerate a dry, hot position, but it will do best and be more lush in reasonable soil.

Hot-coloured border in the former garden of Alida Gray in Sydney; Odontonema tubaeforme in foreground

Hot-coloured border in the former garden of Alida Gray in Sydney; Odontonema tubaeforme in foreground

A spectacular spired shrub that has been in bloom for a while but seems to be at its peak at the moment is Justicia betonica (ht 1-2 m, pictured at the start of the blog), one of the less well-known of the Justicia genus from the family Acanthaceae. The slim upright spires are comprised of papery, green-veined white bracts enclosing pale pink flowers, that last for a very long time. It looks very effective grown next to very dark foliage or nearby white-variegated leaves. Note that in subtropical and tropical areas this plant is considered an environmental weed; it isn't a problem to grow it in Sydney gardens. Another spired Acanthaceae shrub just coming out now is Odontonema tubaeforme (ht 2m, pictured above). It has plumes of blood red, glossy spikes of flowers on a purplish-black stem, providing a vivid contrast. It will stay out for several months.

Dichorisandra thyrsiflora in the garden of Ian McMaugh in Sydney

Dichorisandra thyrsiflora in the garden of Ian McMaugh in Sydney

The so-called blue ginger (Dichorisandra thyrsiflora, ht 1.5 to 2 m), a rhizomatous perennial, produces its spires of vibrant purple-blue flowers in late summer, atop of spiralled, ginger-like stems of leaves. Preferring a shaded spot, it is not a member of the ginger family (Zingiberaceae); it belongs instead to the Commelinaceae family of plants, which includes the various Tradescantia species. Tradescantia pallida 'Purpurea' (syn. Setcreasea purpurea, Tradescantia pallida 'Purple Heart') is a useful (if vigorous) foliage plant with rich purple leaves that can provide colour all year round, and it is a good companion to its cousin the blue ginger in a shaded, semi-tropical style border in Sydney gardens.

Aechmea blanchetiana in the Royal Botanic Gardens Sydney

Aechmea blanchetiana in the Royal Botanic Gardens Sydney

Most ornamental grasses are in flower at the moment and their upright inflorescences add a vertical element to the garden, even though they are not what we would regard as conventional 'blooms', with their feathery plumes. Various cultivars of Miscanthus along with the burgundy-coloured Pennisetum setaceum 'Rubrum' add variety to the scene. Another unusual flower spike out now is that of the huge bromeliad Aechmea blanchetiana (ht 1 m, pictured above). The flower stem, appearing in mid- to late summer, can reach 2 m in height and has feathery yellow and red blooms.

Lobelia siphilitica

Lobelia siphilitica

Amongst smaller plants, I have been delighted with Lobelia siphilitica (ht 60-90 cm) this year. I actually treat this North American clump-forming perennial as an annual, as it fades away after flowering. However, it self-seeds every year and I just dig up these new plants and group them together in a rather damp, sunny border. Clustered spires of blue and white flowers appear at this time of year to form a pretty picture.

Various Liriope, with their dainty spires of tiny bells are in bloom now, adding colour to shady parts of the garden. The flowers range in colour from white and pale mauve to striking purples. Liriope are useful for lining the edges of paths or massed as a groundcover.

There are lots of options for late summer spires in Sydney gardens!