Plant Profile: Trifolium dubium

Lesser Trefoil is an annual weed belonging to the bean family, commonly found worldwide in disturbed areas such as roadsides, meadows, and lawns. As a legume, it plays a vital role in enriching the soil by fixing nitrogen. This plant is often associated with the Irish Shamrock, serving as its inspiration. From late spring to early fall, its small yellow flowers attract bees seeking nectar. Additionally, it can be utilized as animal forage and is frequently seen in lawns due to its resilience against foot traffic and mowing.

While Lesser Trefoil can pose challenges for certain plants (as noted below), it can also offer advantages in specific contexts. For instance, when cultivated in an apple orchard, it has been observed that the resulting fruits may have enhanced flavor.

The flowers of this plant grow in racemes atop elongated stalks, with each raceme typically featuring between three to fifteen flowers.

In terms of pests, diseases, and other plant-related issues, Lesser Trefoil is unable to thrive in shaded conditions. It is advisable to avoid planting it near camellias or gooseberries, as it can harbor a mite that may cause fruit drop in gooseberries and lead to premature budding in camellias.

This species is regarded as invasive.