Native Ground Covers That Solve Slope Problems

If you've got a slope in your garden, you'll know the challenges all too well. Erosion after every heavy rain, plants sliding downhill, and the impossible task of trying to mow grass on an angle that would challenge a mountain goat. Many gardeners look at their slopes as problem areas to be tolerated rather than transformed, but here's the thing—slopes can become the most spectacular parts of your garden with the right approach.

Native ground covers are your secret weapon for conquering difficult slopes. These tough, spreading plants have evolved to handle New Zealand's challenging terrain and weather patterns. They'll stabilise your soil, eliminate the need for precarious mowing, and create stunning displays that work with our landscape rather than fighting against it.

The best part? Once established, native ground covers require virtually no maintenance while providing habitat for local wildlife and adding year-round beauty to previously problematic areas.

Why Slopes Are So Challenging

Before we explore solutions, let's understand exactly why slopes create such headaches for gardeners. The fundamental issue is water—it runs straight off sloped surfaces instead of soaking in, taking precious topsoil with it. This creates a vicious cycle where plants struggle to establish because they can't access adequate moisture, and without plants to hold the soil, erosion gets progressively worse.

Traditional lawn on slopes compounds these problems. Grass has relatively shallow roots that don't effectively bind soil, and maintaining it requires dangerous mowing on unstable surfaces. When drought hits, grass on slopes is always the first to brown off because the water runs away before it can be absorbed.

Exotic groundcover solutions often fail because they're not adapted to New Zealand's specific conditions. That English ivy might look good in a gardening magazine, but it struggles with our summer droughts and clay soils. Meanwhile, aggressive exotic groundcovers can escape into natural areas, causing ecological problems beyond your garden boundaries.

The slope aspect factor: The direction your slope faces dramatically affects growing conditions. North-facing slopes receive intense sun and heat, creating Mediterranean-like conditions. South-facing slopes remain cooler and moister but may struggle with winter drainage. East-facing slopes get gentle morning sun, whilst west-facing slopes endure harsh afternoon heat. Understanding your slope's aspect is crucial for choosing the right plants.

The Science of Soil Stabilisation

Native ground covers solve slope problems through sophisticated root systems that have evolved over thousands of years to handle New Zealand's terrain. Unlike shallow-rooted grass, many native groundcovers develop extensive root networks that penetrate deep into the soil and spread laterally, creating a living mesh that binds soil particles together.

The most effective native groundcovers for slope stabilisation combine several characteristics: rapid establishment, aggressive spreading habit, deep root systems, and tolerance for both drought and waterlogging. They also need to be tough enough to handle the exposed conditions that slopes often present.

Root architecture matters: The best slope-stabilising plants develop what botanists call 'fibrous root systems'—dense networks of fine roots that spread throughout the soil profile. These create thousands of tiny anchors that hold soil particles in place whilst also improving soil structure and water infiltration.

Champion Ground Covers for Different Slope Conditions

Sunny, Dry Slopes: The Mediterranean Mimics

Muehlenbeckia axillaris (Creeping Pohuehue): This is arguably New Zealand's best native groundcover for challenging sunny slopes. It forms dense, weed-suppressing mats that completely eliminate erosion whilst requiring virtually no maintenance once established. The tiny leaves create an attractive carpet effect, and small white flowers in summer attract beneficial insects.

Creeping pohuehue is phenomenally drought tolerant and actually prefers poor soils, making it perfect for those tough clay slopes where nothing else will grow. It spreads rapidly once established—you can expect complete coverage of a slope within 2-3 years from scattered plantings.

Planting strategy: Set out small plants at 1-metre spacings in autumn or early spring. Don't improve the soil—this groundcover actually performs better in challenging conditions. Water regularly for the first season to encourage establishment, then it becomes completely self-sufficient.

Coprosma acerosa (Sand Coprosma): For slopes with a more architectural feel, sand coprosma creates fascinating textural displays with its tiny, needle-like foliage. It forms low, spreading mounds that effectively control erosion whilst adding year-round interest through subtle colour changes from green to bronze.

This coprosma is incredibly hardy and tolerates exposed, windy conditions that would stress other plants. It's particularly effective on coastal slopes where salt spray is an issue. The dense, twiggy growth provides excellent habitat for small native skinks and insects.

Raoulia species (Mat Daisies): These alpine specialists create tight, cushion-like mats that are perfect for smaller slope areas or rock gardens on slopes. Raoulia hookeri forms silvery-grey carpets, whilst R. australis provides bright green coverage. Both are incredibly tough and drought tolerant.

Mat daisies work particularly well for creating defined areas within larger slope plantings or for stabilising particularly steep sections where other plants might struggle to establish.

Shaded Slopes: The Forest Floor Specialists

Selliera radicans (Remuremu): This remarkable native groundcover thrives in the challenging conditions of shaded slopes, particularly those that remain damp in winter but dry out in summer. It produces attractive yellow flowers and spreads via runners to form dense, soil-stabilising mats.

Remuremu is particularly valuable because it tolerates both shade and periodic flooding—conditions that eliminate most other groundcover options. It's perfect for slopes under established trees or in naturally damp areas.

Dichondra brevifolia (New Zealand Kidney Weed): Creating lush, kidney-shaped leaf carpets, this native groundcover is excellent for shaded slopes where you want a more cultivated appearance. It spreads steadily to form dense mats that completely suppress weeds whilst providing excellent soil binding.

This species is particularly useful on slopes where you want to create informal pathways—it tolerates light foot traffic and recovers quickly from minor damage.

Nertera granadensis (Bead Plant): For slopes where you want something truly special, bead plant creates intricate carpets of tiny leaves studded with bright orange berries in autumn. It's slower growing than some groundcovers but creates incredibly dense, erosion-proof mats.

Bead plant is particularly effective on smaller slope areas or as an accent plant within larger groundcover schemes. The berries are beloved by native birds, adding wildlife value to your slope stabilisation project.

Coastal Slopes: The Salt Warriors

Disphyma australe (New Zealand Ice Plant): This succulent native groundcover is absolutely bulletproof on coastal slopes, tolerating salt spray, strong winds, and sandy soils that challenge most plants. The thick, fleshy leaves store water for drought tolerance, whilst purple flowers in summer create spectacular colour displays.

New Zealand ice plant spreads rapidly and forms incredibly dense mats that eliminate both weeds and erosion. It's particularly effective on steep coastal banks where maintenance access is difficult.

Tetragonia implexicoma (Bower Spinach): This sprawling native creates loose, informal coverage perfect for larger coastal slopes. The silvery foliage has a soft, attractive appearance, and the plant tolerates both salt spray and poor, sandy soils.

Bower spinach is excellent for creating naturalistic plantings that blend with coastal landscapes. It's also relatively fast-establishing and provides good coverage within 18 months of planting.

Calystegia soldanella (Shore Bindweed): Despite its common name suggesting an aggressive weed, this native bindweed is actually an excellent groundcover for coastal slopes. It produces large pink flowers and spreads via underground runners to create effective soil binding.

Shore bindweed is particularly useful on very exposed coastal slopes where few other plants will establish successfully.

Establishment Strategies That Actually Work

The key to success with native groundcovers on slopes is proper establishment technique. Many gardeners plant too sparsely, expecting rapid coverage, then become discouraged when results are slow. Here's how to ensure success:

Timing is crucial: Plant in autumn when soil temperatures are still warm but regular rainfall is returning. This gives plants the longest possible growing season before facing their first summer drought. Spring planting can work but requires more intensive watering through the establishment period.

Site preparation: Contrary to what you might expect, don't try to improve challenging slope soils too much. Most native groundcovers actually prefer tougher conditions and can become leggy and less effective in rich soils. Instead, focus on creating stable planting pockets and controlling any existing weeds.

Spacing strategy: Plant closer than you think you need to. For most native groundcovers, 50-80cm spacing gives much faster results than the 1-2 metre spacing often recommended. The slightly higher initial cost pays for itself in quicker establishment and earlier erosion control.

Watering wisdom: Deep, infrequent watering encourages the deep root growth that makes groundcovers effective for slope stabilisation. Daily light watering keeps roots shallow and plants vulnerable to stress.

Mixed Plantings for Complex Slopes

Single-species groundcover plantings can look somewhat monotonous, and slopes with varying conditions often benefit from mixed plantings that combine different species' strengths.

The layered approach: Combine low, tight groundcovers like creeping pohuehue with taller, more structural plants like sand coprosma. This creates visual interest whilst providing comprehensive erosion control.

Seasonal interest combinations: Mix evergreen structural groundcovers with species that provide seasonal highlights—perhaps combining the year-round coverage of muehlenbeckia with the autumn berries of bead plant or the summer flowers of ice plant.

Microclimate matching: Use different species in different parts of the same slope to match varying conditions. Plant drought-tolerant species on the exposed upper sections whilst using moisture-loving types in naturally damper lower areas.

Managing the Transition Period

The most challenging phase of any slope groundcover project is the establishment period—typically the first 18 months after planting. During this time, plants are developing their root systems but haven't yet provided complete coverage, leaving the slope vulnerable to erosion.

Temporary stabilisation: Use biodegradable erosion mats or mulch to provide temporary protection whilst plants establish. Avoid plastic-based products that can interfere with plant growth and create long-term maintenance issues.

Strategic placement: Position plants to intercept water flow and create natural terracing effects. This helps slow water movement whilst providing better growing conditions for establishing plants.

Patience pays: Resist the temptation to over-fertilise or over-water to speed establishment. Native groundcovers develop stronger, more effective root systems when they have to work slightly for resources.

Long-Term Maintenance and Management

One of the greatest advantages of native groundcover slopes is their extremely low maintenance requirements once established. However, understanding the minimal care they do need ensures long-term success.

Annual check-ups: Walk your slope annually to identify any areas where coverage might be thinning or where erosion channels are beginning to develop. Early intervention prevents small problems from becoming major issues.

Weed management: Well-established native groundcover should suppress most weeds, but occasional interlopers may need removal. Hand-pulling is usually sufficient and avoids the risks of herbicide use on slopes.

Edge management: The edges of groundcover plantings often need occasional trimming to prevent spread into areas where it's not wanted. Most native groundcovers respond well to firm edge trimming with a spade.

Beyond Erosion Control: The Ecological Benefits

Whilst solving slope problems is the primary motivation for most groundcover projects, the ecological benefits often become the most rewarding aspect. Native groundcover slopes become habitat for native skinks, insects, and small birds whilst supporting the broader ecosystem connectivity of your garden.

Wildlife corridors: Slopes planted with native groundcovers create movement corridors for small native animals, connecting different habitat areas within your garden and beyond.

Soil improvement: The extensive root systems of native groundcovers gradually improve soil structure and organic matter content, creating better growing conditions for other plants and supporting soil microbiology.

Carbon sequestration: Established groundcover slopes store significant amounts of carbon in both plant biomass and improved soil organic matter, contributing to climate change mitigation.

Your slope doesn't have to be a problem area that you simply endure. With the right selection of native groundcovers and proper establishment techniques, it can become one of your garden's most attractive and environmentally valuable features. The transformation from eroding eyesore to stable, beautiful landscape element is one of gardening's most satisfying achievements—and with native plants, it's entirely achievable for any New Zealand gardener.