Lemon clover is a common plant found in yards, gardens, and other landscapes. It frequently appears in lawns, fields, and disturbed areas. This plant is recognizable by its small, yellow flowers and clover-like leaves.
Identifying Lemon Clover
Identifying lemon clover, Trifolium campestre, involves observing several physical characteristics. Its leaves are trifoliate, meaning they consist of three leaflets, typically oblong or elliptical, measuring about 4–10 mm long. The central leaflet has a short, distinct stalk, while the two side leaflets are often stalkless. Small, leafy appendages called stipules are present at the base of the leaf stalks.
Lemon clover produces small, yellow, pea-like flowers arranged in dense, globular clusters 1 to 2 cm long. These flowerheads resemble miniature hops, giving the plant its common name “hop trefoil.” Each head contains 20 to 40 individual flowers that gradually turn creamy white, then rusty or light brown as they age. The plant typically grows as a low-lying, sprawling, or prostrate herbaceous annual, reaching heights of 10–30 cm.
Lemon Clover’s Role in the Landscape
Lemon clover plays a dual role in the landscape, seen as either beneficial or a nuisance. As a legume, Trifolium campestre fixes atmospheric nitrogen, enriching soil fertility and reducing the need for synthetic fertilizers. This makes it valuable in pastures, as a cover crop, or as green manure, improving overall soil health. Its yellow flowers also attract pollinators like bees, supporting local biodiversity.
Despite its benefits, lemon clover is often considered a weed in manicured lawns and cultivated garden beds. Its ability to spread quickly and form dense mats can outcompete desirable turfgrass or other garden plants. Its opportunistic growth in disturbed areas can be undesirable, especially when it encroaches on intended plantings.
Managing Lemon Clover
Managing lemon clover depends on whether the goal is removal or encouragement. For removal, manual methods like hand-pulling or hoeing are effective, especially for young plants. Ensure the entire root system is removed to prevent resprouting. Cultural practices also help; promoting a dense, healthy lawn through proper mowing height, aeration, and adequate fertilization can suppress lemon clover by reducing available space and light. Applying a 2-3 inch layer of mulch in garden beds can prevent seed germination by blocking sunlight.
For chemical control in lawns, selective herbicides formulated for broadleaf weeds can be used. Follow application instructions carefully to avoid harming desirable grasses. In garden beds, non-selective herbicides may be an option, applied with precision to target only the lemon clover. Conversely, to encourage lemon clover, it can be sown as a cover crop or integrated into low-maintenance lawns for its soil-improving qualities and drought tolerance.
Common Questions About Lemon Clover
Many people wonder if lemon clover is edible. Trifolium campestre is generally considered edible, with its leaves, flowers, and seeds sometimes used in salads or teas, offering a mild, pea-like flavor. However, caution is advised, particularly for individuals sensitive to pollen, as it can cause allergic reactions. Oxalis stricta, also called lemon clover or yellow wood sorrel, has a distinct tangy flavor due to oxalic acid content, but should only be consumed in small quantities.
Lemon clover spreads primarily through prolific self-seeding; seeds disperse when mature pods open explosively. While it establishes readily, it is not typically considered an aggressive invasive species, though it can become problematic if left unchecked. Distinguishing Trifolium campestre from other clovers or similar plants like black medic (Medicago lupulina) involves observing the central leaflet’s distinct stalk and how its flower heads turn brown upon aging, unlike black medic’s black seed pods. Oxalis stricta has heart-shaped leaflets and five-petaled yellow flowers, differing from Trifolium campestre’s oblong leaflets and pea-like flower clusters.