Clover, belonging to the Trifolium genus, is a popular choice that is regaining its former status as a beneficial groundcover for lawns. This low-growing legume offers advantages that can simplify lawn care and improve the overall resilience of the ecosystem. Integrating clover can reduce the need for common inputs like water and fertilizer.
Identifying Suitable Clover Varieties for Turf
The selection of the best clover species for a lawn largely comes down to choosing between two main options, both derived from Trifolium repens, or white clover. White Dutch Clover, the original variety, is characterized by a more vigorous growth habit, typically reaching four to eight inches in height if left unmowed. This type spreads aggressively via horizontal stems called stolons, which root at the nodes to quickly form new plants and fill in bare patches. White Dutch clover produces many globe-shaped white flowers during the growing season, which can be an important consideration for homeowners concerned about bee activity.
Microclover is a cultivated selection of white clover bred to have smaller leaves, roughly one-third the size of the traditional type. It maintains a denser, lower growth profile, blending seamlessly with common turfgrasses like tall fescue or Kentucky bluegrass for a uniform appearance. Microclover is also less prone to flowering when mowed regularly, which reduces the visual impact of the blooms and may be preferable for those with severe bee sting allergies.
White Dutch Clover is frequently used for overseeding existing grass where a higher percentage of clover and a more meadow-like appearance is acceptable. Microclover, while more expensive, is preferred for creating a uniform, mixed-grass lawn where the goal is maximum density and a short, manicured look. Other clover types, such as Red Clover or Crimson Clover, are unsuitable for permanent turf due to their taller growth, clump-forming habit, and short lifespan.
Functional Advantages of Clover in Lawn Ecosystems
One of the greatest benefits of integrating clover into a lawn is its ability to perform nitrogen fixation, which is a natural fertilization process. Clover is a legume that forms a symbiotic relationship with specific soil bacteria, primarily Rhizobium, which colonize the plant’s roots in specialized structures called nodules. These bacteria convert atmospheric nitrogen gas, which plants cannot use directly, into ammonia, a nitrogen form that is readily usable by the clover and nearby grass plants.
This process supplies a continuous source of nitrogen to the soil. The nitrogen is released primarily when clover clippings decompose after mowing or when older clover plants die back. Research indicates that a clover content of 20 to 30% in a grass sward can offset the need for applied nitrogen fertilizer.
Clover species possess a deeper, more extensive root system compared to many common turfgrasses. This root structure allows the plants to access moisture deeper in the soil profile, increasing the lawn’s tolerance for drought and heat. Clover-integrated lawns often remain green during periods of low rainfall when pure grass lawns may turn brown. The dense, spreading growth habit of clover shades the soil surface and crowds out many broadleaf weeds. This natural competition minimizes the need for chemical weed control.
Establishing and Maintaining a Clover Lawn
The optimal time for seeding is either in the early spring, before the grass begins vigorous growth, or in the late summer and early fall, approximately eight weeks before the first hard frost. This timing allows the seeds to germinate and establish roots during the cooler, moister conditions that clover prefers.
Soil preparation should include aerating the area and ensuring the soil pH is between 6.0 and 7.0, a range that supports both the clover and the nitrogen-fixing bacteria. When overseeding an existing lawn, the grass should be mowed closely, and the soil should be lightly raked to expose the surface and ensure good seed-to-soil contact. Clover seeds are extremely small and should be mixed with a carrier like fine sand or sawdust to help achieve an even spread across the area.
After seeding, the area must be kept consistently moist for the first seven to fourteen days to ensure strong germination and seedling survival. Once established, the long-term maintenance requirements are lower. Mowing is optional but can be done to maintain a tidy appearance, with the mower set to at least three inches in height to encourage the smaller leaf size of Microclover.
Avoid using broadleaf herbicides, as these products will kill the clover. Homeowners should also stop applying nitrogen-heavy fertilizers, which favor turfgrass growth and allow it to outcompete the clover. Instead, if the lawn requires a boost, applying a fertilizer with phosphorus and potassium can strengthen the clover without stimulating excessive grass growth.