Steep slopes and banks are vulnerable to erosion, but you can’t rely on just any plant to stabilize a hillside or steep bank. The slope also carries water away down to the bottom, so a hard rain running down the slope can pull at your plants and stress them without giving them a deep watering. Choosing the best plants for steep slopes in Australia means considering the watering challenges presented by slopes as well as the climate and sun exposure.
Much of Australia tends to be hot and dry, so the best plants to stabilize a steep bank in Australia should be hardy and drought-resistant. If you live in a more temperate region like Melbourne or a tropical region in the north, you may have more options in choosing ground cover plants for slopes since the temperatures tend to be milder and your plants will receive more rainfall.
Fast Growing Ground Cover for Slopes
If you need to cover a steep slope in a hurry, forget about grass! For one thing, no one wants to try to mow that. The best plants for steep slopes prefer well-draining soil, have deep roots, and are drought-tolerant. If you’re not planning on terracing or building retaining walls, you’re probably looking for a ground cover for slopes with low maintenance needs. Fast growing ground covers for slopes often have low growing habits so they can quickly cover open ground.
Best Ground Cover for Slopes in Full Sun
Coastal rosemary is a native Australian plant and landscaping favorite. The Westringia genus has a lot of low-growing varieties that require little to no maintenance, and they flower all year round. The hardy coastal rosemary has evolved to handle the salty sea spray, strong winds, harsh sunlight, and dry soils common to the coast. Even if you don’t live near the coast, coastal plants tend to be hardy and able to handle the tough conditions often found on sloping terrains.
Commonly known as Jug Flower, Adenanthos cuneatus is another low-growing groundcover suited for sunny areas on Australia’s western coasts and southern regions. When exposed to full sun, the leaves turn shades of pink and red, and the year-round flowers offer nectar for small honey-eating birds and insects.
If you have a particularly barren slope on your hands and want to prevent weeds from setting up shop, the evergreen Grevillea ‘Bronze Rambler’ grows quickly and forms a dense weed-resistant cover. Another Grevillea cultivar option is ‘Poorinda Royal Mantle,’ which prefers arid to temperate zones (no tropics!) and spreads quickly over open ground.
Best Ground Cover for Shady Slopes
It’s difficult to find plants that tolerate shade, so a shady slope can be extra difficult to landscape! Generally, look for dark green foliage as a sign of a shade-loving plant. For example, the Midgen Berry (Austromyrtus dulcsis), a low-growing shrub, prefers part to deep shade and is a good option for humid climates. For shady, dry areas, many varieties of Acacia are low-growing and prefer well-drained, sandy soil.
Many shade-loving plants tend to be slower-growing. If you live in a humid subtropical region like Brisbane, succulents like Echeveria glauca can thrive in shade and spread quickly. Plants that can handle both shade and very dry soil are rare specimens. Correa pulchella ‘Pink Eyre,’ a native evergreen shrub, is one such plant. For a more grassy plant, Dianella caerulea ‘King Alfred’ is another option. The spreading and climbing Bluebell Creeper shrub (Sollya heterophylla) blooms often and requires little care.
Using Pioneer Plants for Slopes
Pioneer plants are so named because they quickly grow, spread, and dominate any available space. They aren’t always the best plants for steep slopes if you want to cultivate a landscape with variety, since they tend to push out all other plants. This can be a good thing if you’re mainly concerned with weed control and erosion control, and are dealing with poor soil. Pioneer plants like Bleeding Heart (a low bushy plant with tell tale heart-shaped flowers) and Sarsaparilla (a climbing vine plant) can then be considered.
Other pioneer plants for hostile environments include Pigface, acacias, and Spinifex grasses that do well in coastal sand dunes can also provide spreading ground cover and erosion control on slopes.
Succulents and Cacti as Ground Cover for Slopes
The shallow roots of most succulents and cacti make them a poor option for erosion control, but if erosion is not a serious concern they can work well in arid regions. Succulents have colorful fleshy leaves covering much of the color spectrum. Some cactus varieties have soft spines or none at all, and there are also creeping varieties that work well as ground cover.
Ground Cover Plants for Steep Slopes Australia
Although low-growing, spreading plants are a common choice for ground cover plants for sloping gardens, shrubs and bushes can add visual interest and root deeply for added erosion control. Although not ideal as a fast growing ground cover for slopes, once established, shrubs and small trees can help protect the soil and surrounding plants from damaging erosion. A mix of shrubs, trees, and low-growing plants offers the best erosion control. Trees that stay small
One method of damage control to help struggling trees and shrubs is to create a terrace at the same level as the plants or build a basin around the plants to retain some water instead of letting it wash away. For extensive projects to alter the drainage of a slope, add bank stabilisers, or make it easier to access, Normark professional landscapers can help!
Consider a shrub like Hardenbergia ‘Bushy Blue’ Hardenbergia for steep slopes, which is fast-growing and can be shaped or left to grow as it pleases. Its branching habit makes it a good ground cover. Saltbushes are another low-growing shrub that can form a dense ground cover even on a hostile site. The Swan River pea is another sub-shrub option that can also be trained into climbing.
Combining hardy shrubs and small trees with cascading ground covers like Creeping Boobialla and Ground Morning Glory provides a high level of soil retention. However, since Australia contains a multitude of climates, a local landscaper, like Normark in Melbourne, can address your unique needs and concerns as well as help you tackle larger projects.