White Clover (Trifolium repens)
White clover is one of the most common lawn weeds across New Zealand. While it’s highly valued in pastures for its nitrogen-fixing ability and stock feed benefits, it’s far less welcome in lawns. Its creeping habit, white flowers, and bright green leaves can quickly disrupt the uniform look of a well-kept lawn.
White clover spreads through above-ground runners called stolons, which root at the nodes and form new plants. It thrives in lawns that are low in nitrogen or moisture-stressed, often becoming dominant where grass is thin or underfed. It’s also remarkably resilient to mowing, drought, and some herbicides, which is why it can easily become a persistent nuisance.
Identification
White clover is easy to identify by its three round leaflets and distinctive white markings on each leaf. The leaves are smooth and hairless, unlike subterranean clover which has fine hairs. Each leaflet grows from a central point, forming the typical “three-leaf” clover shape.
The plant spreads flat across the soil via creeping stolons, which root as they go. This allows white clover to spread quickly and survive mowing. In late spring and summer, it produces round, white flower heads made up of many small florets. These flowers attract bees, which can be a problem for anyone walking barefoot on the lawn.
White clover can sometimes be confused with strawberry clover, but strawberry clover produces small, bladder-like seed heads after flowering, while white clover does not.
Why It’s a Problem in Lawns
Although white clover adds nitrogen to the soil, in a home lawn it usually signals poor fertility or weak grass growth. It thrives where grass is struggling—particularly in dry, compacted, or low-nitrogen areas.
Once established, it spreads rapidly through its stolons, forming dense patches that crowd out grass. These patches often remain greener through dry weather, which makes them stand out even more. While some homeowners tolerate it, most find its patchy growth and bee-attracting flowers undesirable.
Control in Home Lawns
White clover can be controlled effectively with the right herbicides and improved lawn management. The key is to treat it while it’s actively growing and then correct the underlying soil or fertility issues that allow it to thrive.
Best control methods:
- Physical removal: Small patches can be dug out by hand, ensuring you remove as much of the stolon network as possible. Any remaining roots can quickly regrow.
- Chemical control: Use selective broadleaf herbicides containing clopyralid (NZLA BWC), dicamba, triclopyr, or picloram (NZLA Gold). These actives provide excellent control of mature clover. Avoid composting treated clippings for several months as residues may persist.
- Cultural management: Fertilise regularly with a nitrogen-rich lawn fertiliser to help grass outcompete clover. Maintain moderate mowing heights and irrigate deeply but infrequently to strengthen grass roots.
Prevention Tips
- Apply a balanced fertiliser in spring and autumn to maintain good nitrogen levels.
- Keep the lawn dense by overseeding thin patches in autumn.
- Aerate compacted areas annually to improve soil structure.
- Avoid mowing too low; longer grass shades the soil and discourages clover seedling growth.
- Water deeply and less often to promote deeper grass roots and discourage shallow-rooted weeds.