My Acanthaceae journey

Sunday, 19 February 2012

White form of Justicia carnea, an excellent plant for shaded areas

I have had a passion for warm-climate Salvia for the past 15 years and they have become a vital part of my sunny borders, giving colour and form all through the year. In more recent times, I have become interested in warm-climate plants to suit the shadier sites in my garden, especially those that grow easily without the need for too much cosseting and fussing. I seem to be getting lazier these days! So I've developed a great fondness for plants from the family Acanthaceae, a number of which grow and flower well in shady places - even quite dry shade. They generally thrive in very ordinary soil and need little attention other than a hard prune annually (usually in late winter). Many Sydney gardeners will be familiar with some of these plants, as a number of them have been grown here since the 19th century. Early colonial gardeners found that plants from such genera as Strobilanthes (called Goldfussia in those days), Justicia (known as Jacobinia in earlier times), Thunbergia and Ruellia thrived in our mild climate: in England, they had to be grown in heated greenhouses.

Brillantaisia subulugurica, a long-flowering Acanthaceae plant

There are a number of less commonly seen types that also grow very well in our climate, such as Brillantaisia subulugurica, Pachystachys lutea and Rhinacanthus beesianus species. The range of flower forms in the family is broad (including bells, spires and claw-like shapes); and often it is the showy bracts of the inflorescence that are the most attractive feature, and these last for ages on the plant. The plants usually have interesting foliage - colourful, textured or of a large size that provides a good foliage background feature. In every season there is a variety of plants from the family Acanthaceae in bloom in Sydney.

Justicia brasiliana, another unusual member of the family Acanthaceae

At the moment in my garden, some of my favourite members of the family that are in bloom include a quartet from the genus Justicia. Justicia carnea is probably the most familiar, with its showy pink or white plumes that continue from summer into autumn on a shrub 1.5 m tall. It is an excellent plant for a shady border, amongst shrub or cane Begonia, Plectranthus species and Hydrangea. A less well known species just coming into bloom now is Justicia brasiliana, (previously known as Dianthera nodosa), which is a small shrub (ht 1 m) with dainty, fan-like, pink blooms on arching branches - again thriving in shaded areas. Justicia betonica (ht 1 m) has upright spires of green-veined white bracts enclosing pale pink flowers and is sometimes called the white shrimp plant, as it looks a bit like the more familiar shrimp plant - Justicia brandegeeana - that blooms practically all year round in our climate, with reddish-pink or lime-green 'prawn'-like inflorescences comprised of curving bracts holding small white flowers.

Pachystachys lutea, a showy member of the family

Over the past months, my passion for these easy-going Acanthaceae plants led me to research their history in Sydney gardens, to investigate the current nomenclature within the family, to discover which ones grow best here, and to explore some suitable companion flowers and foliage to grow with them. During my Acanthaceae journey, I met some very enthusiastic gardeners who shared my interest and learned how they grew these plants in their gardens. I have collated the information into an illustrated booklet about the family Acanthaceae, covering 34 species from 15 genera, similar to my previous Salvia publication. I have tried to give an honest evaluation of each plant, including their foibles as well as their positive points. I have provided some propagating tips and have also found where it's possible to buy many of these plants. Booklets are now available for purchase: Please click here for more information.

If you have some shaded areas in your garden that need to be filled with something undemanding but attractive - consider the family Acanthaceae! They are perfect plants for Sydney - or any other warm temperate climate.