Had enough yet? The drought continues and the few isolated bursts of rain have done little to relieve moisture-stressed plants and lawns. Many lawns and parks in my neighbourhood are crispy brown, and certainly don’t invite a picnic or barefoot romping with the dog. Turfgrasses protect themselves by going dormant during drought, and will grow new green blades when rain returns to replenish soil moisture to a minimum standard.
Although I don’t have an in-ground irrigation system, my own lawn is reasonably green because of white clover (Trifolium repens) I’ve sown into the grass. (Of the four species of clover seed available, only low-growing white clover is suitable for lawn use.) White clover is deeply drought resistant and remains green during a prolonged absence of rain. It was commonly included in turfgrass seed mixes before weed-killing herbicides for lawns were available. Clover is a legume, not a grass, and selective herbicides designed to kill weeds in grass (such as 2,4-D, dicamba and MCCP) also kill clover, and consequently it was eliminated from the seed mixes. Like other legumes, white clover grabs nitrogen from the air and fixes it in solid nodule form on its roots, feeding itself and sharing the meal with neighbouring grass plants. It’s a good plant to have underfoot.
Now that the province of Ontario and other areas don’t allow the use of synthetic herbicides, it’s a good time to bring back white clover in lawns. We don’t need to be concerned about keeping the lawn uniform or looking like a golf green, because it’s virtually impossible to achieve those standards without the use of herbicides. But we can do something about keeping the lawn green in drought periods. White clover seed can be purchased at garden centres or from online seed suppliers (oscseeds.com). It grows to about six inches in height (15 cm) and has a rounded leaf with pale white markings. It’s easily grown with grass and can be cut with the lawn mower.
I overseed the lawn in August to keep it thick, alternating a grass seed mix one year, followed by white clover seed the next year. (The grass seed needs to be covered with peat moss or soil to keep it moist, but white clover seed doesn’t require covering.) Use white clover seed as sparingly or as generously as you like. In traditional seed mixes, white clover was included as 10 per cent of the seed content, with the remaining 90 per cent made up of lawn grasses. I use it generously, and would like my lawns to be 50 per cent white clover, so that when drought comes, the lawn will stay green.
White clover seed germinates in about 14 days in cool, moist conditions during spring or late summer. The first sowing produces clusters of young clover plants that begin to spread out in the second season. The small round clover leaves are visible in the lawn, but are much more attractive than dandelion leaves. And they’re certainly the right colour.