White clover identification and control

White clover Trifolium repens

A member of the legume family, white clover is a common weed in managed turf areas.

Appearance

The are many varieties of this low-growing perennial weed but white clover is the one most commonly found in lawns.

It is easily identified by its characteristic leaf structure of three leaflets (trifoliate) at the end of a long stalk.  Each leaf is vaguely tear-shaped and a white coloured crescent is often visible towards the bottom.

Trifolium repens

The flowers are white in colour but are sometimes tinged with pink and are attractive to many insects. They are generally produced between May and October and measure around 15-20 mm in diameter.

Growth habit

A low growing perennial weed with creeping, spreading stems along which roots will readily grow.

Conditions that favour its development

Found on all types of soil but most commonly on medium to heavy alkaline soils and where fertility is generally low.

It can also tolerate dry conditions as it has a deep tap root with which it anchors itself into the ground.

Together with its ability to ‘fix’ nitrogen and store it in its root nodes, it is often seen looking nice and green during dry summers while the grass has suffered and turned brown.

Cultural control

White clover is a persistent weed, often tolerant of close mowing and can be difficult to control with cultural methods alone.

• Remove small plants by hand before they become too widespread.
• Ensure that grass plants receive adequate nutrition, applying a suitable lawn fertiliser at regular intervals throughout the growing season to create a dense, healthy sward to minimise spaces for weed invasion and to maintain competition against the clover. Avoid fertilisers containing phosphorous that can favour the growth and development of the clover.
• Rake/brush the sward prior to mowing to lift flowers and leaves to aid removal. Always box-off clippings to retain plant debris.
• Mow regularly and at an appropriate cutting height for the conditions to remove flower heads prior to the clover setting seed and to maintain sward density.

Chemical control

White clover can be controlled relatively easily using a selective herbicide.

Products containing the active ingredient(s) mecoprop-P and/or dicamba will provide the most reliable control with clover usually being eliminated after one or two applications.

Always apply when the weed is actively growing, usually between April and October.  Repeat if necessary.