Tough low hedges

Sunday, 15 January 2017

Low box hedge in the garden of Kerrie and Steve Babian in Sydney

Disheartened by this ongoing Sydney heatwave (will it ever end?), my spirits were lifted last week by a visit to a favourite garden in a nearby suburb, where well-established plantings were showing great resilience to the very trying conditions. In this garden, created by my friend Kerrie Babian, who has a fabulous eye for design, there are a number of excellent hedges of different heights used to create structure and privacy. On this occasion, I was especially drawn to the use of low hedges to delineate different areas of the garden and decorate them too.

Hedge of Lavandula dentata previously grown in the garden of Kerrie and Steve Babian in Sydney

It's intriguing how lining up a set of plants creates something more than the sum of the parts: providing a strong visual statement, helping to sculpt and define spaces in the garden, and giving a calm, uniform background to looser, less structural plants. Low hedges can also play these powerful roles in gardens, particularly those of a more compact size, where towering hedges look totally out of place. Some plants for low hedges lend themselves to tight clipping to create a formal, geometric look, whereas others have a naturally dense shape that creates a more organic-looking profile without much need for pruning. Other plant specimens can be treated in either way.

Hedge of Loropetalum chinense Pixie Purple in the garden of Kerrie and Steve Babian in Sydney

At the entrance to the garden, in front of a set of beautiful sandstone walls, a pair of hedges of a new dwarf form of burgundy-leaved Loropetalum chinense has been planted in recent times. The original species is a shrub that actually eventually achieves the proportions of a small tree, but this delightful form, 'Purple Pixie', grows only 30-50 cm tall and 1.2-1.5 m wide, with pink flowers in spring. It needs just occasional clipping to remove wayward stems. Previously, this area had been planted with low hedges of Lavandula dentata (pictured in previous paragraph), the so-called French lavender, which looked fantastic and which was the best choice for Sydney's humid climate, but lavender hedges do have a shelf life here, and they eventually became too woody and were removed.

There are forms of dwarf English box (Buxus sempervirens species) but in this garden, the naturally taller Japanese box (Buxus microphylla), which generally thrives in Sydney, is used and clipped to a low height (shown at the start of the blog). In the herb garden, it gives a crisp form amongst the surrounding plantings and forms a striking feature that looks great all year round.

Hedge of Salvia leucantha Santa Barbara in the garden of Kerrie and Steve Babian in Sydney

Atop a wall in the back garden, in front of a taller Murraya paniculata hedge is another very successful low hedge, this time using the short cultivar of Salvia leucantha known as 'Santa Barbara'. Unlike the species, which can become rather rangy and lax, 'Santa Barbara' sits up very nicely indeed, and grows to 60 cm tall, with the gorgeous purple flower spikes rising to about 90 cm in late summer and autumn. It is in bloom for a long time. Trimmed back lightly after flowering, then pruned hard at the end of winter, it regrows to a neat plant with slim, textured, grey-green leaves, and its naturally dense, rounded shape provides the contour of the hedge. It thrives very well in a hot, dry position - my own plant grows near my letterbox at the top of a battleaxe drive, and is never given any extra water.

Josie the dog surveys one of the Liriope hedges in the garden of Kerrie and Steve Babian in Sydney

In shaded parts of Kerrie's garden, a large form of Liriope is used to make a different sort of low hedge, along the tops of walls and dividing the entertaining area from the herb garden. Its grassy form gives a more fluid effect, and it is one of the toughest plants that anyone can put into their garden, enduring shade and drought without turning a hair (or should that be 'leaf'?). In this garden, it is cut back very hard in late winter every few years, and it regrows fresh new foliage. Other lower-growing Liriope varieties (and their cousins, the mondo grasses) can also be used in this way to define areas or to grow along an edge of a pathway, and there are a number with attractive variegated leaves. Even such clump-forming strappy-leaved perennials as Agapanthus and Tulbaghia violacea could be used in the same way.

Decorative foliage of Nandina domestica Nana in autumn

Another plant I have seen over the years in other gardens grown as a low hedge is the dwarf Nandina domestica 'Nana', which has a naturally compact form (ht 45 cm) and needs no clipping. Its dainty, vaguely bamboo-like leaves take on pretty red, orange and even purple tints in autumn, and because it doesn't lose its leaves, these remain decorative all through winter. The foliage colour is developed best when the plants are grown in a hot, dry spot. In spring, it has very attractive lime green new growth. It is another sturdy plant, which can put up with very hot, dry situations as well as shady spots.

Hedge of low form of Rhaphiolepsis indica in the garden of Alida Gray in Sydney

The low-growing forms of the Indian hawthorn (Rhaphiolepis indica) are also good subjects for a dense hedge, with the added advantage of pretty pink or white flowers in spring. These are also resilient plants and will cope pretty well with dry conditions and heat once established. Another flowering shrub for a low hedge is Cuphea hyssopifolia, which has tiny leaves and petite, starry flowers of white or purple, growing only about 60 cm tall. I have seen it in a nearby garden clipped in a superb low circular hedge around a plinth. It will grow in sun or light shade. There is a gold-leaf form. Murraya paniculata 'Min-A-Min' grows to only 1 m tall, and could be a useful low hedge, with the added attraction of fragrant flowers and lush green leaves.

The Australian native known as coastal rosemary (Westringea fruticosa) is a good candidate for a low hedge, especially the new cultivar 'Grey Box', which grows 30-45 cm tall and as wide. Frost and drought tolerant, it can grow in sun or light shade, and can be clipped one to three times a year for a formal shape, or left unclipped for a looser look. It has dainty grey foliage and white flowers from spring until autumn. There are some low-growing lilly pillys around these days too, which could be useful hedges, such as Syzygium australe 'Tiny Trev', growing to 75 cm, with attractive shiny green leaves.