Clover, most commonly recognized as Trifolium repens in Australian lawns, is a pervasive broadleaf weed that can quickly take over turf where grass struggles to thrive. Its distinct three-leaflet structure and low-growing, creeping habit make it a noticeable presence in an otherwise uniform lawn. This article details the practical, science-based methods for eliminating clover and implementing a long-term strategy to ensure it does not return.
Changing Lawn Conditions to Discourage Clover
Clover is a member of the legume family, able to convert atmospheric nitrogen into a usable form through a symbiotic relationship with bacteria in its root nodules. This allows clover to thrive in nitrogen-poor soils where turfgrasses struggle, giving the weed a distinct competitive advantage. Addressing this nutrient imbalance is one of the most effective non-chemical methods for control.
By supplying the lawn with adequate nitrogen fertilizer, the turfgrass is strengthened, and the soil environment becomes less favorable for clover establishment. Increasing the mowing height is also a simple but effective cultural control method. Clover is a low-growing plant, and raising the mower deck to around 7 to 8 centimeters (3 to 4 inches) allows the turf blades to cast shade over the clover, starving it of the sunlight it needs to grow.
Hand-pulling is a viable option only for small, isolated patches of clover. The plant spreads via stolons, so the entire root system and stolon must be removed to prevent re-sprouting. Watering practices should also be adjusted to favor the lawn over the weed, meaning watering deeply and infrequently to encourage strong, deep grass roots that can outcompete the shallow-rooted clover.
Targeted Herbicide Options for Australian Lawns
For widespread clover infestations, applying a selective broadleaf herbicide is the most efficient method. Selective herbicides are formulated to target broadleaf weeds, like clover, while leaving the desirable turfgrass unharmed.
Always check the herbicide label against your specific lawn type, as certain Australian turf varieties are highly sensitive. Common active ingredients include combinations of Dicamba and MCPA. However, Dicamba-based herbicides are not recommended for soft-leaf Buffalo lawns (including Sir Walter varieties) because they can cause severe damage or death. If you have Buffalo grass, select a product explicitly labelled as “Buffalo-safe,” often relying on active ingredients like Bromoxynil and MCPA.
Couch and Kikuyu grasses tolerate Dicamba and MCPA combinations better than Buffalo. For maximum efficacy, apply the herbicide when clover is actively growing, typically during spring (September–November) or autumn (March–May). Apply the product in the early morning or late afternoon when temperatures are mild, avoiding the hottest part of the day to prevent reduced effectiveness and turf burn.
Avoid mowing the lawn for two to three days before and after application. Withhold watering for at least 48 hours following the treatment. This allows the systemic herbicide to translocate throughout the entire plant, including the stolons and roots, ensuring complete eradication.
Ensuring Clover Does Not Return
Achieving long-term clover control depends on maintaining a dense, healthy turf that physically prevents the weed from establishing. A professional soil test will provide accurate information regarding the soil’s pH and nutrient levels, particularly nitrogen.
This information allows for the development of a precise fertilization schedule tailored to the lawn’s needs. A high-nitrogen fertilization program, matched to the specific turf variety, maintains the vigorous growth that inhibits clover.
Overseeding the lawn with a suitable, locally adapted turfgrass variety is another technique to increase density and crowd out potential weed germination sites. Overseeding should be done after initial clover control has created bare patches. A dense turf canopy shades the soil surface, inhibiting the light required for clover seeds to germinate and establish new plants. By combining appropriate fertilization with cultural practices that promote a thick, healthy sward, the lawn becomes its own best defense against clover re-establishment.