If we wish to build sustainable landscapes, they must be self-sufficient without requiring constant mulch and fertiliser. One of the key ways to achieve this it to use the ‘chop and drop’ method of biomass accumulation. A successful chop-and-drop mulching system uses a mix of plant types that each offer unique benefits to soil health, carbon cycling, and ecological resilience. Below are a few key categories of plants to prioritise, with guidance on their functions and best-use strategies.
True Clumping Grasses
These grasses form dense, basal clumps with narrow, often upright foliage and a non-invasive habit. Their key value lies in producing long, fibrous leaves that are rich in carbon and silica. This creates a slow-cycling mulch that resists rapid breakdown, ideal for protecting soil from erosion, suppressing weeds, and building long-term humus.
Clumping grasses also respond well to cutting, regrowing with renewed vigour. Because they’re typically shallow-rooted, they partner well with deep-rooted species in multi-layered systems. Best used along contours, bunds, and erosion-prone sites.
Cenchrus purpurascens ‘PA300’ Trade Name Nafray®. This variety is extremely tough and seeds rarely if ever lead to viable new plants, meaning it’s not weedy compared with other forms. https://www.ozbreed.com.au/plant-ranges/native-grasses/nafray-cenchrus-is-a-compact-drought-tolerant-native-grass-ornamental-native-grass/
Fibrous Strappies (e.g. Dianella, Lomandra, Liriope)
These robust monocots offer dense, fibrous foliage with architectural form and extreme resilience. They are highly tolerant of pruning and neglect, regrowing reliably even in poor soils or exposed sites.
While they don’t grow as quickly as true grasses, their foliage contributes slow-release carbon that improves soil texture and water-holding capacity. Many species also produce dense root systems that stabilise soil and support microbial life, particularly when planted in clusters or bands along slopes and swales.
Dianella ‘DCNC3’ PBR Intended Trade Name Baby Breeze™. This Australian flax has been bred to be much tougher than other forms, especially when it comes to its cutback performance. See how low it was pruned here, and it bounced right back a few weeks later. https://www.ozbreed.com.au/plant-ranges/strappy-leaf-plants/baby-breeze-dianella-2/
Woody Trees and Shrubs
Grevillea species are particularly valuable in nutrient-poor environments due to their proteoid roots, which release organic acids to extract phosphorus and other minerals from insoluble sources. This makes them excellent partners for companion species, particularly where soil fertility is limited. Many Grevillea respond well to coppicing or hard pruning, producing flushes of fresh, nitrogen-poor biomass that’s high in lignin — perfect for slow breakdown. However, established roots are sensitive to phosphorus, so care should be taken not to over-fertilise. Avoid wet feet, especially in clay soils.
Another of the most versatile woody species for chop and drop, Callistemon tolerates repeated pruning and thrives under a wide range of conditions. Unlike Grevillea, they are not sensitive to phosphorus and often thrive in heavier or wetter soils. Their woody branches offer excellent long-term carbon input, while soft, nutrient-rich foliage can be used to balance slower materials in compost or mulch. Many cultivars are highly adaptable, withstanding both drought and occasional inundation, making them ideal backbone species for long-term soil building.
Slim™Callistemon viminalis ‘CV01’ PBR. Instead of raking clippings, allow them to mulch the soil. Or, leave them in their natural shape and coppice them low every few years, allowing all that biomass to return to the soil. https://www.ozbreed.com.au/plant-ranges/native-shrubs-groundcovers/slim-callistemon-is-a-great-hedge-for-tight-planting-areas-native-shrubs-ground-covers/
Nitrogen Fixers (e.g. Acacia, Casuarina, Hardenbergia)
Nitrogen is both air-soluble and water-soluble, meaning it’s constantly escaping the system via leaching and volatilisation. Nitrogen-fixing plants form symbiotic relationships with specific bacteria to convert atmospheric nitrogen into a usable form for plants. Because they’re adding N to the system, chopping their leaves is a great way to fertilise the soil.
Meema™ Hardenbergia violacea ‘HB1’ PBR. Vegetation is fast to break down, and is generally high in Nitrogen. Think of plants like this as living fertilisers. https://www.ozbreed.com.au/plant-ranges/native-shrubs-groundcovers/meema-hardenbergia-is-a-longer-lived-shrubby-groundcover-plant-native-shrubs-ground-covers/
Dynamic Accumulators
These are plants that are able to source nutrients that other plants find hard to source, especially with the use of deep roots. The classic dynamic accumulator is the deep-rooted comfrey, however a range of Australian native plants may be useful for this purpose including Proteaceae members such as Grevillea and Banksia with their proteoid root systems.
By incorporating nitrogen-fixing trees trees and shrubs, shrubs or groundcovers, you create a renewable source of living fertiliser. When their soft foliage and green stems are chopped and dropped, they not only contribute nitrogen but help break down carbon-heavy mulch, accelerating decomposition and nutrient cycling. Include both fast-growing pioneers and long-lived N-fixers in your system for continuous benefit.