Clover is a broadleaf legume, not a grass, and its presence can break the uniform appearance desired by many homeowners for a traditional lawn. This plant thrives in conditions that often stress turfgrass, creating patches that compete with the desired monoculture. Replacing a clover-heavy lawn with a solid stand of grass requires a methodical approach, starting with strategic timing and removal, followed by careful soil preparation and long-term maintenance.
Pre-Removal Planning and Timing
Establishing a new lawn requires careful planning, particularly regarding timing and material selection. For cool-season grasses like Kentucky bluegrass or tall fescue, the optimal seeding window is late summer to early fall, typically mid-August through September. This timing allows seedlings to establish deep root systems before winter dormancy, utilizing cooler air temperatures and warm soil.
If your region uses warm-season grasses such as Bermuda or Zoysia, seeding should occur in late spring or early summer when soil temperatures consistently reach 65 to 75 degrees Fahrenheit. A soil test is an important first step, as it reveals the soil’s pH and nutrient levels. Clover often indicates nitrogen-poor soil, and knowing the current balance allows for the targeted application of amendments to favor grass growth.
Eliminating the Existing Clover
Clover removal can be accomplished through chemical or mechanical methods, depending on the area size and preference for herbicides. For chemical control, a selective broadleaf herbicide containing active ingredients like 2,4-D or dicamba is effective against clover without harming existing grass. Applying the herbicide during the fall is advantageous because clover plants are actively transporting nutrients to their roots for winter storage, helping deliver the chemical deep into the root system.
To maximize effectiveness, apply the herbicide on a calm, dry day when temperatures are between 65 and 80 degrees Fahrenheit. Wait at least two days after mowing to allow clover leaves to regrow, ensuring enough surface area to absorb the product. For a manual approach, smothering large patches with opaque plastic sheeting deprives the clover of sunlight. Smaller patches are easily removed by hand, but the entire root structure must be removed to prevent regrowth.
Preparing the Ground and Planting Grass
Once the clover is eliminated, the ground requires significant preparation to create an ideal seedbed. If the area was heavily compacted, till the soil to a depth of four to six inches to loosen it for better root penetration and water drainage. Incorporate necessary soil amendments, such as lime to adjust pH or compost to improve structure, while tilling so the materials are mixed deep into the soil.
After tilling, rake the area to remove debris and achieve a smooth, level surface, as high or low spots can lead to uneven growth and drainage issues. Apply a starter fertilizer with a high phosphorus content (e.g., 10-20-10) to promote strong root development in the new seedlings. The grass seed should be spread evenly, lightly raked to a planting depth of about one-quarter inch, and then gently rolled to ensure good seed-to-soil contact.
Installing Sod
If installing sod, lay the pieces in a staggered, brick-like pattern to prevent seams from aligning, which helps with stability and water distribution. After the sod is laid, immediately roll the entire area with a water-filled roller to press the turf firmly against the prepared soil and eliminate air pockets. Regardless of the method, the initial establishment phase requires intensive watering to keep the top inch of soil consistently moist, preventing the seeds or sod roots from drying out.
Maintaining the New Lawn and Preventing Clover Return
The long-term goal is to cultivate a dense, healthy turf that naturally crowds out any returning clover. One effective cultural practice is maintaining a higher mowing height, typically around three inches or more. Taller grass blades cast shade onto the soil surface, which suppresses the germination of clover seeds and other broadleaf weeds.
Clover is a nitrogen-fixing plant, allowing it to thrive in poor soil. By consistently applying a nitrogen-rich fertilizer, you shift the competitive advantage back to the grass, which needs high nitrogen levels to flourish. Once the lawn is established, watering deeply but infrequently encourages the grass to develop deep, drought-tolerant roots, helping it outcompete the shallow-rooted clover.
As a preventative measure, a pre-emergent herbicide can be applied in subsequent seasons to stop clover seeds from germinating. Apply it in early spring before soil temperatures reach 55 degrees Fahrenheit, and again in the fall before the first hard frost. These consistent cultural practices create an unfavorable environment for clover, ensuring the new lawn remains dominant.