A great way to provide color and texture to many areas of the border is to use ornamental grasses. Planting grasses in a naturalistic fashion or as designer features both add interest color and form. Jan Carson shares her experiences and some ideas on the use of ornamental grasses.
Ornamental Grasses for Gardens and Landscaping
Over the last ten years the use of ornamental grasses in our gardens has steadily increased in response to the overseas trend to more naturalistic planting, and also a desire to create something more uniquely Australian in our gardens.
Images from the UK, USA and Germany of both public and private gardens have opened our eyes to the diverse realms of grass gardening, beyond our tentative beginnings with Pampas Grass in the 1960’s, (only to realise its potential as an environmental weed in the 1980’s). The advent of the Sydney Olympics rightly precipitated a new approach to broad scale amenity planting, and a brief to feature native Australian plants gave many of us our first chance to appreciate the drama of broad swathes of single species of grass and their ability to enliven what otherwise might have been bland slopes with their dynamic texture and movement.
Our experience with the Pampas Grass was a salutary one that should always serve to remind us of the necessity of wise species choice lest we further overload our bushlands or indeed our agricultural industries with yet another recalcitrant weed. The original Pampas clumps were of a single cultivar and remained self-sterile until we introduced other colour forms, which promptly allowed cross-fertilization and a proliferation of wind borne seed. During my work as a bush regenerator I was still coming across isolated specimens whose seed had drifted in to otherwise quite intact pieces of bushland even quite recently.
Responsible selection of grass species and strict attention to overseas experience in areas climatically similar to our own still gives us the opportunity to select from a wonderful palette of garden grasses, both native and introduced.
Those of us who garden close to bushland or in pastoral areas naturally always need to be particularly care full with new plants of all types, and I cannot emphasize too strongly the need to deal with anything that presents a weed potential swiftly and to notify the appropriate authorities. I cannot personally agree with the use of some grass species (eg Panicum, Phalaris arundinacea etc), when overseas experiences has shown them to be prolific self-seeders or aggressive runners, and at Eastcoast Perennials we refuse to market these, appealing as they might be.
So let’s turn our attention to some gardener friendly grasses that you might not yet be familiar with. I’ll start with one of my favourite genera, the Carex. The Sedges encompass some of the most diversely colourful, neat and hardy smaller evergreens of all the grass families. You should be aware by the way that I am using the term “grass” fairly broadly, to cover not only the family Poaceae (the true grasses), but also the Sedges, Rushes and Restios, with their tremendous range of variety in leaf and inflorescence.
Ornamental Grasses for the Garden
Carex oshimensis is one of the most polite and useful of grasses, happy in full sun or quite deep shade, in dry years or wet ones, and with maintenance requirements of almost zero! How nice can a plant get? The plain form is a neat little arching clump of soft shiny flat forest-green blades, presentable all through the year. Small brown lizard-like flowers appear in late spring. Individual plants cover an area of maybe 35cm in diameter but are not quite that high.
Carex oshimensis ‘Evergold’ is its variegated form, each slightly slimmer and longer leaf with a broad pale creamy-gold central band edged in green. A wonderful plant to light up difficult dry shade areas.
Carex morrowii is a shorter leaved more leathery sort that is now available in Australia in its variegated form. Here the colour is grass green with a broad edging stripe of creamy lemon, the clump short and tufty. Similar requirements to the above.
Carex elata ‘Aurea’ is Bowles’ Golden Sedge, a stunning form originally found on England’s Norfolk Broads. The leaves are clear golden yellow with fine and irregular green striping. The spring foliage is absolutely stunning and if it is sited in damp soil, say by a pondside, or with some amount of light overhead shade, the effect will last through summer. A naturally moisture loving plant, it will also do well placed on a shallow pond terrace in a pot. A quick trim to 10cm or so in early autumn will neaten it up for winter and allow the spring display to come through unimpeded. It grows to 80cm or so.
Carex comans is the New Zealand Hairy Sedge, not hairy leaved, but each plant looks rather like a head of bouncy brunette hair after an auburn rinse! Fine arching bronze-tan leaves rising to 40cm. Many people’s first reaction to seeing a brown leaved grass is to classify it as “dead looking”, and if seen placed against bare earth or mulch this can be pretty close to the mark. But if instead you like to imagine the same “dead grass” interspersed through drifts of Gaura ‘Pearly Pink’ or with bright green Carex oshimensis and mauve dwarf Penstemon, or perhaps low silver leaved plants and weathered stones, you will start to get a very different picture.
These sorts of groupings have the natural repose of a meadow or alpine grassland, a very relaxed and informal style of gardening. Perhaps you have inherited some 1960’s conifers in your garden? Modernize them by adding a selection of wind-mobilised grasses in drifts, thus adding life to an otherwise static scene.
Luzula nivea is the Snowy Woodrush, and though not in the same family, it bears many resemblances to the Sedges in general form, being a smallish clumper, spreading only slowly to form a little patch. Its flowers, though not terribly showy, are pleasant little bobbly white clusters, and the soft grey foliage is quite distinctly white-hairy! Part shade suits this one and a soil moist to moderately dry. It does not tend to rot like many hairy things in humid weather even though it is from central and southern Europe and the Alps.
Miscanthus sinensis is a wonderfully stately and formal grass, something in the way of a much smaller Pampas, with fluffy plumes held aloft in late summer and autumn. It is sun loving and deciduous, that is, its leaves die back each winter. For best appearances it should be cut back low each year, once the winter winds start to break down its form. This allows the new foliage to come through cleanly in spring, and is best accomplished with gloves and a pair of garden scissors, assuming that you don’t have the luxury of a whipper-snipper or hedging tool.
Miscanthus sinensis is a clumping grass that can grow to 2m or more depending on variety. In general it presents no problem with self-seeding, although there are reports of some of the early flowering cultivars producing unwanted numbers of offspring in the warm southern states of the USA. Our attitude at Eastcoast Perennials is to hold the sale of any implicated cultivars until the extent of this problem is clarified for Australia. It is certainly not a problem in our colder states and here the only few seedlings we have had have been within the precincts of the sprinkler system.
The flowerheads (of the fine leaved cultivars particularly), make excellent dried flowers that do not shed their silken fluff and remain beautiful for years. Pick them when they first begin to fluff out during the day.
Miscanthus sinensis ‘Gracillimus’ or Maiden Grass, is an antique cultivar grown in Western gardens for over 100 years and still one of the best. This is a fine-leaved sort with the characteristic central white leaf stripe of its species. Forms an arching fountain-like clump to 1m, topped with soft copper-pink 2m feathery flower heads in late summer, ageing slowly to buff.
Miscanthus sinensis ‘Silberfeder’, (Silverfeather), combines the wider leaf and more airy graceful habit of the variegated sorts with the white-ribbed leaves of the fine-leaved cultivars. It is a plant of great stature. The flower plumes emerge silver-pink and age to pure silver. Allow a little more room for this one as it is not only tall at 2.1min flower, but tends to arch gracefully.
Miscanthus sinensis ‘Variegatus’ is striped in grey-green and white along the length of its leaf blades. This grass is perhaps the most elegant of the Miscanthus, its pale growth and willowy arching habit very telling in the garden. I love it with sombre wine-reds and purples as a contrast, but is also great with cheery things like Dahlias, daisies and Bergamots.
Stipa gigantea is a grass much used in English flower borders but it hails from Portugal, Spain and Morocco. The low thin but stiff grey-green foliage is completely eclipsed in early summer by enormously tall shimmering oat-like panicles that age to a shining gold. Now grown for several years in Victoria, it has shown no propensity to self-seed there and we are currently trialling in hopes of confirming that status for NSW. It is clump forming and only the tall flower stems need be removed annually to keep it neat. It resents wet soil in winter and should have an open sunny position in more warm humid areas.
Themeda triandra is our native Kangaroo Grass (not to be confused with our Wallaby Grass, which is another story). It inhabits many ecosystems from the eastern sea-coast headlands, where it forms a soft low lawn, to the Eucalypt forests of the Great Dividing Range where you see it as a scattered understorey of individual clumps each rising to 50cm or so when in flower. Interestingly it is also found in South Africa and is a seasonal food source for some of their large herbivores!
A soft leaved pale green arching clump, with considerable but not unsightly cinnamon-tan thatch, topped with tan triangular flowers on fine dangling stems. It is pretty as both a fresh and dried flower.
Poa labillardieri was one of the ornamental grasses used so effectively to cloth the open slopes around the Homebush Olympic site. It is a large shaggy thing consisting of very fine inrolled leaves of grey-green, topped in season with airy sprays of jade-green flowers ageing to buff. Quintessentially Australian in look, it adds an immediate air of naturalness to native plantings and also looks very well with bold daisies such as Echinops or Echinacea.
Poa labillardieri ‘Suggan Buggan’ is an exciting new form of “Poa lab” (as it is known in the trade), with slightly flattened erect and very very blue-grey leaves along with a tall stately column of flower plumes. This is doing well for us under trial here and we will probably be offering it in the future.
Poa poiformis is a similar creature to Poa lab and a better choice for seaside gardens and/or wet soils. Its foliage is jade green.
Poa sieberiana ‘Mr Curly’ is a plant originating at Eastcoast Perennials from seed collected from a purple-stemmed form of the species. ‘Mr Curly’ is a dwarf with very fine bright green foliage. The previous season’s creamy-buff foliage is held within the new green growth and when dry it contracts into a soft fuzz of ringlets amongst the green tuft. In damp or humid weather, (or when you turn on the sprinkler), it unfurls to become erect again. A charming native rockery pet, comb it gently with your fingers to remove broken leaves occasionally.
Care of Ornamental Grasses
As a general rule, maintenance for ornamental grasses involves only an annual clip when their appearance seems to warrant it after flowering, although some, like the Carex, never even need this. Don’t be tempted to cut them down too early either, as many are just as eye-catching when they have “hayed off”, (as farmers would say), to shades of buff, gold or tan. The weather will usually dictate the correct date to cut, but in good years many will hold beautiful skeletal outlines well into winter, often made even more lovely by frost or morning dew.
Application of fertilizer is seldom needed except perhaps in a new garden on impoverished soil just to get them started, and can often be counterproductive in established gardens as a more upstanding and compact plant is produced on a low fertility soil.
Watering here for our grasses is fairly minimal once they are established, but those gardening in dry summer Mediterranean climates may need to give a little on occasion in summer if plants look obviously stressed. Mulch, of course, is part of the natural cycle in grasslands and you will do well to emulate Mother nature when caring for onamental grasses in this regard.