Botanic Garden lessons

Sunday, 08 March 2015

Hibiscus schizopetalus, Royal Botanic Garden, Sydney

I have always loved visiting Sydney's Royal Botanic Garden since childhood, but more especially since the time I had an epiphany whilst walking along its paths about 15 or so years ago on a hot February day. Surrounded by lush semitropical plants in full and luxuriant bloom, it suddenly occurred to me that I should be taking note of what was right in front of me, instead of what was illustrated in my genteel English gardening books. My attempts to reproduce a herbaceous English-style border in my humidity-ridden Sydney garden were half-baked at best, and in the steamy weather of February, many of my delicate European perennials dropped dead overnight - being completely out of their comfort zone and clearly not cut out for life in Sydney. In retrospect, it was hardly an earth-shattering realisation - but it seemed it at the time, when many Sydney gardeners were caught up in the cottage garden craze.

Since that fateful day, I have visited the Royal Botanic Garden in Sydney many times - in fact, whenever I go into the city I try to have at least a short walk in there. Since I became open to what it has to tell me, I have learned many valuable gardening lessons. A stroll in there last week reminded me of a number of these.

Succulent display, Royal Botanic Garden, Sydney

Obviously, the most important message that the Garden gives is to plant according to the climate in which you find yourself. Plants from the top of tall, snow-capped mountains in Europe are not going to thrive in Sydney gardens as well as those from semitropical regions such as South and Central America, Mexico, and parts of Africa and Asia that have climates quite similar to ours. Many of the plants in the Botanic Garden come from these regions and flourish mightily. In English gardens, they can only be grown outdoors in summer and have to be put in glasshouses during winter!

Dichorisandra thyrsiflora in the Begonia Gardens, Royal Botanic Garden, Sydney

The Garden showcases a number of different plant groups, revealing how very suited they are for our own home gardens. The Begonia Gardens, for example, are a triumph, especially right at the moment when the flowers seem to be at their very peak - each plant dripping with blooms. These areas are planted in a naturalistic way like an actual large garden, with a canopy of tall plants such as Brugmansia sheltering the lower planting; paths meandering in and out of the borders; and a layered mix of Begonia plants of all types and heights - including cane-stemmed, shrub-like and rhizomatous - with other shade-loving plants of different foliage textures, such as ferns, Dichorisandra (pictured above with Begonia), Clivia and Philodendron, to form a complete landscape. Begonia are perfect for our climate, flower over a lengthy period (from November to June or longer in mild suburbs), have attractive foliage, suffer no pests and diseases, and are shade-loving. What more could we ask of a plant!

Rhinacanthus beesianus

I gained my love of the Acanthaceae family of plants from seeing so many examples of them in the Sydney Botanic Garden. These plants - among them Justicia, Ruellia, Eranthemum, Megaskepasma, Odontonema and Strobilanthes species - have been significant in the Garden since the 19th century; a number of keen gardeners in colonial times imported them soon after their discovery in the wild by plant hunters and they were popular garden plants at that time. These plants prosper extremely well in Sydney with very little care, and many flower outside of spring, giving welcome colour in the other seasons. Autumn probably sees the most number of specimens in bloom. Many of these plants will grow and flower well in shaded areas. I enjoyed seeing the scalloped-edged pristine white flowers of the tall shrub Rhinacanthus beesianus (pictured above) last week in the Garden - a Chinese plant previously identified in the garden only as a Pseuderanthemum species.

Bromeliad planting, with Aechmea blanchetiana in foreground, at the Royal Botanic Garden, Sydney

Planted under an enormous tree in the Garden is a wide variety of bromeliads, thriving in quite dry shade. The colours and patterns of the foliage of these tough plants form a wonderful tapestry, and over the years I have copied this solution to dry shaded spots in my own garden. Bromeliads were anathema to me in my English-garden years, but I now embrace them as perfect plants for the Sydney climate!

Amaryllis belladonna with Strobilanthes dyeriana at the Royal Botanic Garden, Sydney

Whereas I once tried (futilely) to grow rare, delicate bulbs from the Himalayas and Europe in my garden, the Botanic Garden taught me that I would have much more success with warm-climate bulbs, especially those from South Africa and South America. My garden is now replete with bulbs such as Amaryllis belladonna (pictured left in the Royal Botanic Garden, Sydney, with Acanthaceae plant Strobilanthes dyeriana), Babiana , Freesia, Watsonia, Hippeastrum and Scadoxus - many with flamboyant inflorescences that mingle well with the surrounding semitropical plantings.

Massed Calathea and Ctenanthe under a tree, Royal Botanic Garden, Sydney

Another lesson I have learned from the Botanic Garden is the value of massing plants. Of course, in the Garden there is plenty of space for having a large planting of the same specimen whereas in our home gardens we are often trying to squeeze in as many different plants as we can. However, seeing a tree underplanted with just a few different shade-tolerant plants such as Ctenanthe or Calathea,as shown above, one realises how coherent and effective it can look. I do now try to plant at least more than one of each type of plant and make a group!

The Botanic Garden has a milder microclimate than many Sydney suburbs because of its proximity to the harbour, and contains a number of plants that are too cold-sensitive for my cooler garden half an hour away. However, I have been encouraged to push the limits in using semitropical plants in my garden by being inspired by what is grown in the Garden. During every visit, I see something new. Last week it was the delightful pendulous blooms of Hibiscus schizopetalus (pictured at the start of the blog), like exotic lanterns, that caught my eye and I started to ponder on where I might be able to grow one at home ...