Pest type: Plants
Clover is a low-growing, drought tolerant perennial that reproduces through the growth of stolons, or runners, which spread horizontally through stems located just at or below the ground. There are nearly 250 species of clover in the world, with red, crimson, and white (dutch) as the most familiar. A variety of low growing white clover called microclover is also becoming increasingly popular for use in turfgrass, as it can provide all the benefits of clover yet remain somewhat hidden by allowing grass to grow above it.
Clover was not always considered a weed. In fact, 75 years ago, every lawn contained some amount of clover. Incorporating this three leaved (four if you’re lucky!) plant into public and private green spaces is a great idea. Here’s why:
Contrary to the perception that clover is an eyesore, the plant will remain verdant green all year round. This is because clover, as a member of the legume family, is able to “fix,” or accumulate nitrogen from the air through beneficial soil bacteria that form nodules on its roots. Clover makes quick use of this nutrient, with data showing that roughly 75-80% of its nitrogen is stored in its topgrowth. Clippings left on a lawn after a mixed grass-clover turf is mowed can provide a significant source of free nitrogen. Sowing roughly one to two ounces of white clover per 1,000 sq ft. will provide a lawn with between 5 and 10% clover cover (up to 10 ounces for the whole lawn to be a bouquet of clover). At this rate, leaving clippings on the lawn will add between one to two pounds of slow release nitrogen per 1000 square feet. For many soils and grass types, this is enough nitrogen to eliminate the need for any additional nitrogen fertilizer applications over the course of the year.
In addition, clover’s benefits extend below the surface to soil-dwelling organisms. Studies performed on grazing lands show that when clover is mixed into grass-dominated landscapes, earthworm abundance increases. Research published by van Eekern et al. in the Journal of Applied Ecology in 2009 found that planting grass-clover mixtures provide a wide range of positive benefits to the landscape and increase soil health and microbial diversity.
Clover is useful in a number of other areas apart from the lawn. Plant a ring of pure clover around your garden to both attract earthworms and deter rabbits, which will stop at the clover before reaching your veggies. Also use it as a ground cover, to accent walking paths, or as a cover crop during the winter months. Let pure clover stands grow around your garden and “chop and drop” by letting it grow out and using the cuttings as nitrogen-rich mulch.
For folks who want the economic benefits of clover, but are still concerned about aesthetics and less enthused about attracting pollinators, microclover is a new option on the market. It will grow lower than grass and produce fewer flowers while still remaining dark green and fixing nitrogen from the air. DFL organics and EarthTurf are two companies which specialize in grass-microclover seed mixes.
Bringing clover back into American lawns is predominately a cultural issue. It requires a change in perception about what constitutes an aesthetically pleasing landscape, and education about the ecological benefits and cost-savings that clover can provide. Let the clover already present flower, and don’t be afraid of seeding more. Yes, your lawn will contain small white flowers, and yes, you’ll attract bees to your yard, but you know that’s a good thing for your wallet and the environment, and when your neighbor asks what you’re doing, you’ll be ready to respond.
Look at your product labels and try to avoid products containing those chemicals listed below:
(A = acute health effects, C = chronic health effects, SW = surface water contaminant, GW = ground water contaminant, W = wildlife poison, B = bee poison, LT = long-range transport)