Justicia betonica

During a recent discussion with gardening friends about low-maintenance plants, someone mentioned the genus Justicia, one of my favourite plant groups. The only requirement they have is pruning - they seem prone to no pests or diseases. They will put up with ordinary soil and are quite drought tolerant; and a number of them will grow in shady parts of the garden! Justicia belong to the family Acanthaceae (one of my favourite families!) and they comprise the largest genus in that family, with more than 700 species. Justicia are native to warm temperate to tropical areas in the Americas, India and Africa. They are generally frost sensitive. They are perfect plants for Sydney's climates as they are unfazed by our summer heat and humidity and enjoy our mild winters. Those that do best here are generally evergreen shrubs, and there are some attractive ones in bloom at the moment.

Justicia brasiliana

Justicia brasiliana

One of those catching my eye right now is Justicia brasiliana (ht 1 m), which has recently come into bloom, with its pretty pink, fan-like flowers that appear in the leaf axils and cascade down along the arching branches. It blooms from late summer all through autumn. It tolerates part or dappled shade and will thrive in spots under trees even where there is some root competition. It is a useful underplanting for the other shade-loving shrubs flowering in late summer and autumn, including Camellia sasanqua and cane and shrub Begonia.

Justicia betonica with dark-leaved canna

Justicia betonica with dark-leaved canna

Justicia betonica (ht 1-1.5 m) is also in full, magnificent bloom. It is sometimes called the white shrimp plant or squirrel's tail on account of its long-lasting summer blooms, which are held in slim upright spires and are comprised of papery, green-veined white bracts enclosing pale pink flowers. Unlike most Justicia, this species does best in a sunny position. It looks good paired with very dark foliage, such as purple-leaved Canna for drama or with a background of shrubby Euphorbia cotinifolia, and it is also very effective grown with white-variegated foliage plants.

Justicia brandegeeana Red form

Justicia brandegeeana Red form

Also called shrimp plant is the well-known Justicia brandegeeana (ht 1-1.2 m) with clustered reddish-brown overlapping bracts which resemble cooked prawns! It will flower well in part or dappled shade, and in a protected warm position may flower all year, though it is at its best in summer and autumn. It looks good with dusky leaves (such as those of Persicaria 'Red Dragon) and also looks effective with the reddish-orange flowers of Fuchsia triphylla hybrids. The yellow-flowered version ('Lutea') has lime-yellow bracts, which associate well with lime-leaved plants such as Duranta 'Sheena's Gold' or the golden version of Salvia elegans. A pink-flowered, lime-bracted cultivar called 'Fruit Cocktail' is an interesting variant.

Justicia carnea

Justicia carnea

Another familiar species is Justicia carnea (ht 1.5 m), sometimes known as the Brazilian plume flower or jacobinia. It has large, lush leaves and thick plumes of white, pale pink or deep pink tubular flowers that appear in regular flushes from early summer to late autumn. Occasional deadheading will promote repeat flowering. It is useful for shaded sites, even quite heavy shade. It is a good companion to hydrangeas, Plectranthus species and ferns. The lovely white form looks pretty with silver-leaved companions, such as Plectranthus argentatus and Pilea cadierei.

Justicia scheidweileri

Justicia scheidweileri

The smallest Justicia that grows in my garden is just starting to come into bloom now. Sometimes known as rose pine, Justicia scheidweileri is a groundcover (ht 20 cm) with attractive silver-veined leaves and chubby spikes of burgundy-bracts enclosing mauve flowers, from early autumn to spring. It is quite shade tolerant and I like to grow it amongst silver-leaved rhizomatous Begonia or velvety silver groundcover Plectranthus 'Nicoletta', to echo its foliage markings. It also looks pretty nearby coleus with pinkish or burgundy leaf markings.

Justicia aurea

Justicia aurea

Late autumn and winter will see the flowering of other Justicia species in my garden. Looking like a golden-yellow version of Justicia carnea, Justicia aurea (ht 1.5 m) is sometimes known as yellow jacobinia. This is another species that seems to bloom better in sun than in shade. It is a cheering sight in winter, with its big feathery flowers, and combines well with yellow-variegated foliage, such as that of Euonymus japonicus 'Aureus' or with the blue winter flowers of Salvia 'Costa Rica Blue'.

Justicia floribunda with clivias in the garden of Robin Diehm in Sydney

Justicia floribunda with clivias in the garden of Robin Diehm in Sydney

Throughout winter and spring, Justicia floribunda (syn. Justicia rizzinii, ht 1 m), sometimes known colloquially as firefly, lights up my garden with its dainty, pendulous, tubular-bell shaped flowers, each multi-toned in colours of scarlet, orange and yellow. It will bloom in sun or shade and is so useful for those dry, shady spots that exist in every garden. The airy effect of its blooms provides a pretty contrast to more robust flowers that appear in winter and/or early spring, such as orange or yellow Clivia or scarlet poinsetti. Shrubby Abutilon with their Chinese lantern blooms in a similar range of hot colours are also particularly floriferous when firefly is at its best and they look good together.

Justicia adhatoda

Justicia adhatoda

The other species I grow in my garden blooms in late winter and early spring. Justicia adhatoda (ht 4 m) is one of the tallest of the genus. It has large attractive shiny leaves that have a lime tinge in their new growth; the flowers - appearing in late winter and spring - are held in spikes and they have the typical two-lipped form, similar to those of Acanthus mollis, and they are white with a purple netting on the lower lip. It grows best in heavy, part or dappled shade areas, and it will tolerate dry soil. It will flower more prolifically in a sunny spot but in such a position the leaves tend to become rather yellow, and they wilt in hot weather. This shrub forms a good background screen to lower plantings.

All Justicia can be easily propagated from cuttings taken in spring or autumn. I generally prune my specimens quite hard in late winter, except for those that are still blooming at that time - as soon as they finish flowering, I cut them back. I look forward to possibly finding some more Justicia someday.