For years the main specialist native hedging plants have been Lilly Pillies. They are fine for shaded or general conditions, but in hot, dry, exposed and windy sites they can struggle. Now there are a number of new specialist native hedging and screening plants that love exposure, with unique Westringia and Callistemon plants leading the way.
Part of the reason for the revival in hedging plants is the increased use of low cost long arm and standard hedge trimmers that can hedge plants in a fraction of the time. Pruning can be done more often at a lower cost of time and money, and without the back-breaking work. If you haven’t tried one yet you don’t know what you’re missing.
Many exotics like English and Japanese Box make good hedges but are a little slow to establish. Murraya, Viburnum, and Photinia are widely used as screens and larger hedges, and are ideal for many situations, but for hot, exposed and windy sites they can struggle at times. For most years they will be fine, but in Australia every now and then we get extreme heat and wind. Most of our capitals experience 40 to 45 degree days with hot winds at some time. This is when plants are truly tested. Even Acmenasmithii can be tested in these situations. Add severe drought to the equation, finding plants that survive our tough, sun burnt country can be hard. With all the rain on the East Coast lately, it is easy to be lulled into a false sense of security and not plan for the certain return of drought, heat, and hot winds.
In years gone by certain species of native plants like Callistemon, Westringia, Leptospermum and Melaleuca have survived these harsh periods very well, but most cultivars are poorly suited to hedging. Their internodes are not spaced right, or the shape is wrong, or they get untidy after a few years. Breeding has improved many of these plants to the point that they now make great hedging and screening plants for hot exposed conditions. Some exotics like Raphiolepisalso cope with these conditions. Some of the best forms of this plant are recent releases, such as Oriental Pearl. It is ideal for use in smaller hedges, and has dark green shiny leaves and lots of white flowers in spring. Cosmic Pink is a small Raphiolepis with pink flowers that makes a nice hedge with regular pruning. Cosmic White will make a medium sized hedge with the same dark green leaves and even larger white flowers. These three plants set very little seed, making them a safer choice, and were bred by Vic Ciccolella.
Moving back to the natives, Callistemon and Westringia are known as some of the most reliable landscape plants, however, over time they do have a habit of opening up and becoming woody if used as a hedge.
New breeding by Nuflora, Sydney University and Ozbreed has resulted in many new hedging and screening varieties with much better performance. As a screen plant for exposed situations there could be nothing better than Slim, a new Callistemonviminalis. It has a natural thin shape, and has foliage all the way from the ground up. Slim flowers profusely in spring and autumn and its dense foliage responds well to trimming. There are not a lot of plants that can cope with growing next to a tin shed or fence that gets radiated heat from the sun, but this is one of them. Growing to about 3 metres, this can be top cut to 2 metres, or left to grow to its full height. Pruning once per year is certainly enough, but with long arm trimmers being so easy to use, pruning two times per year will make Slim tighter and more vibrant. Prune just after it flowers.
Red Alert is another Callistemon but with many differences. It gets vivid red foliage in autumn and spring making it a colourful alternative to Photinia. It has yet to ever flower, which believe it or not is a good thing for schools, play grounds and day care centres where bees and seed pods are often unwanted. Red Alert hedges grow from about 1 metre, to an ultimate height a few years down the track of 2 metres if you want it that high.
Scarlet Flame makes a more compact hedge from about 80cm to 140cm. This one gets colourful foliage in autumn and spring as well, and has fine leaves making it a dense tidy hedge. It was bred from Captain Cook, but is at least half the size. Scarlet Flame flowers in spring, and often in autumn. Prune these two plants at least two times per year, but if they are pruned three to four times the result is amazing. Pruning more often makes for tidier hedges. Now that hand shears have been replaced by brilliant machines, this process is as easy as mowing your lawn.
Westringias have been widely used as hedging plants, but after a while they tend to become untidy. Recent breeding has changed the way we think about Westringia forever. New releases like Aussie Box and Grey Box have very short internodes, making them far tidier. Aussie Box is best suited for hedges about 50 to 70 cm, whilst Grey Box is best for 30 to 50 cm. These plants can also be pruned into their natural ball shape. Aussie box has green foliage with mauve flowers, whilst Grey Box has grey foliage with white flowers. Both cope with hot, exposed windy sites well and even perform right on the coast being bombarded with salt laden winds.
If you want a ground cover type hedge about 30cm to 40cm high and a metre or more wide, then Mundi is the best answer. Pruned regularly this makes a tidy low, flat and wide hedge with prolific white flowers in spring. Aussie Box and Mundi are best pruned at least two times per year as a hedge, but if you prune them four times or more per year, they look spectacular. Regular pruning like this keeps them tight and tidy, and greatly extends their life as a hedge. Grey Box only needs pruning twice per year to achieve the same result.
For years people have used Grevillea plants like Robyn Gordon and Superb for hedges, and Leptospermum or Melaleuca plants such as Snowstorm. Hedging more often with modern machinery will now improve their performance as hedges. A new Leptospermum called Sea Shore is a very small compact form, ideal for hedging in the non humid parts of Australia. It tolerates salt laden winds very well.
If you have heavy shade Lilly Pillies, Murraya or English and Japanese box will make better hedges than the abovementioned plants, but for those harsh hot, dry and wind swept positions these new Aussie Natives are ideal. New better hedging machines like long armed trimmers have made it easy to trim more regularly resulting in even better looking native hedges.
Images (top to bottom): Aussie Box-Grey Box; Red Alert; and Scarlet Flame.