“Mow the existing lawn short and rake out any thatch buildup so that the small clover seed has contact with the soil,” she says. “Mix the tiny clover seed with sand, compost, or soil to aid dispersal. 1-2 ounces of clover seed is needed for every 1,000 square feet of lawn.”
White-clover seed comes in many varieties and is readily available by mail order or at local gardening stores.
Says Sharapova, “Prior to World War II, lawn grass seed mixes actually contained clover seed. [But] by the 1950s, with aggressive marketing by chemical companies of synthetic herbicides … clover became identified as a weed.”
The War on Clover
Here’s the short answer: Clover wasn’t always considered a weed. It just got branded as one.
“Clover also draws up and accumulates trace minerals. When clover decomposes, it makes the minerals available to the lawn grass and soil life. The grass becomes more disease resistant because of the health benefits of clover.”
“Clover … crowds out broadleaf weeds because it quickly forms clumps that spread by secondary roots, or stolons,” says Sharapova. In agriculture too, clovers are common and successful “cover crops” according to studies like this one in 2015 . When sown in between major crop plantings, they keep weeds down on farm fields for the upcoming year. This helps cut down on herbicide use and costs, too.
Clovers — specifically Trifolium repens — have for centuries been domesticated ground cover plants or livestock forage plants. Clover is a legume, in the same plant family as peas, beans, and peanuts. Its common names include white clover, white Dutch clover, Dutch clover and ladino clover. While it is native to the Mediterranean, it was introduced into the United States early in the colonial days. By 1747, it was common enough that Benjamin Franklin noted red clover’s value in improving pastures. Today, it grows readily from Canada to Texas, from Florida to Alaska.
Fresh white clover seed that has not suffered abrasion from mechanical harvesting or soil action has a high percentage of impermeable seeds and is largely dormant. Scarification increases the level of seed germination from 21 to 99%. Light has no effect on germination. In the field, seedlings emerge from February to November but mainly from March to May. In a sandy loam soil, field seedlings emerged from the top 0-30 mm of soil with most from the surface 20 mm.
Seed dispersal is important for the colonization of new habitats. Apparently-viable seed has been found in samples of cow manure. White clover was the most numerous seed to survive in dairy farm manure that had been composted. Seeds survived passage through sheep. Most seeds were destroyed after 3 months in a dung heap but 5% remained viable. Viable seeds have been recovered from wormcast soil. Passage through the earthworms increased the germination of both hard and non-hard coated seeds.
White clover is widespread in pastures and meadows, frequently cut grass verges and lawns. It is absent from tall grass. It often occurs as seedlings on arable land. In unsown set-aside land in Scotland, white clover was the most frequently recorded species and constituted the second highest ground cover. In a study of seedbanks in some arable soils in the English midlands sampled in 1972-3, white clover was recorded in 59% of the fields sampled in Oxfordshire and 53% of those in Warwickshire but only in low numbers. White clover seed was found in 9% of arable soils in a seedbank survey in Scotland in 1972-1978.
Where seeding is prevented, white clover can survive almost entirely through vegetative reproduction. The creeping shoots root at the nodes and can form a large clonal patch. Plant longevity is difficult to estimate but some clones are known to have survived in situ for over 60 years.
White clover is tolerant of heavy grazing, trampling and cutting. In undergrazed pasture it is suppressed by the taller growing grasses. The time of grazing can affect the growth of white clover relative to the grass. Heavy grazing of a white clover/perennial ryegrass sward in March, April and May leads to a substantial increase in white clover at the expense of the ryegrass. Grazing after April leads to a decline in the white clover but not of ryegrass. The frequency and intensity of grazing may also affect the relative balance of different clones or cultivars of white clover within a field. The highly selective nature of sheep grazing can have a differential effect on white clover clones. The leaves of different cultivars often have characteristic white marks and sheep have shown a distinct bias towards particular markings. White clover is trample resistant and high stocking rates on grassland can cause a shift in species composition in favour of white clover and perennial ryegrass.