What if, instead of being environmental offenders, lawns could be contributors to the well-being of our landscapes? That’s the question Dr. Eric Watkins has been addressing in his work at the University of Minnesota, and he is coming up with some intriguing answers. For almost a decade now he’s been creating lawns that are not only more sustainable, requiring far less inputs to remain green and growing, but also hospitable to native bees and other pollinators.
The grasses on which Dr. Watkins has been basing his lawns are various mixtures of the species known as fine fescues. This group includes a number of different types: hard fescues, creeping red fescues, chewings fescues, and sheep fescues. They have long been an important component of the “shady mixes” of grass seed you’ll find at the local garden center or big box store, although they actually grow quite well in situations of full sun as well. As the name suggests, they are finer textured than most other turf grasses, with thin leaf blades.
I’ve planted a few lawns composed of mixtures of these grasses and found them quite adaptable, though they won’t tolerate poorly drained, consistently damp soils. They have several advantages over other turf grasses. I was interested in them because they are naturally short and so need far less mowing — I mow my own fine fescue lawn about once a month, and a friend for whom I installed such a lawn, who doesn’t mind a somewhat tousled look, mows just twice a year, once in late spring and again in late summer.
A lawn’s need for fertilizer, as Dr. Watkins points out, will vary with the soil on which it is growing, but he has found that a fine fescue lawn typically needs just a half to a quarter the amount of fertilizer as a Kentucky bluegrass lawn would on the same site. The fine fescues — and Dr. Watkins likes to plant mixes of the different types to increase the genetic diversity and adaptability of the resulting turf — are as a group are outstandingly drought tolerant once established, although they do require irrigation during periods of prolonged heat and dry weather. If you select fine fescue seed that contains endophytes, a beneficial fungus that lives within the grass, the lawn will also be naturally resistant to diseases and to many turf-eating insects.
An interesting characteristic of the fine fescues is that they are clump-forming, growing as a collection of discrete plants. As they establish themselves, they will fill in to make a solid, and weed-resistant carpet, but they can coexist with sprinklings of low-growing flowering plants that make them hospitable to pollinators: “bee-friendly.” Dr. Watkins has been experimenting with including white clover, creeping thyme, and self-heal (Prunella vulgaris). Increasing the biodiversity of the lawn in this fashion greatly increases its attractiveness to pollinators; the University of Minnesota researchers have found over 50 species of native bees visiting their bee lawns.
To maintain populations of the flowering plants, the bee lawn cultivator must avoid the use of broadleaf weedkillers, another advantage from an environmentalist’s perspective. Applications of insecticides will kill pollinators, and so these too should be avoided. Added to these benefits is the fact that such bee-friendly lawns have a smaller carbon footprint because they require so much less mowing, fertilizer, and water.
The state of Minnesota has taken a hand in encouraging such plantings with a “Lawns to Legumes” program that offers grants to gardeners to convert conventional turf to such bee-friendly lawns. It offers a “Planting for Pollinators Habitat Guide” with comprehensive instructions on how to accomplish this, available for free download from its Board of Water and Soil Resources website that is most easily located by conducting a web search for “Lawns to Legumes.”
For more information, listen to a conversation with Dr. Watkins about bee-friendly and sustainable lawns on the Berkshire Botanical Garden Growing Greener podcast at www.thomaschristophergardens.com/podcasts/bee-friendly-lawns
Be-a-Better-Gardener is a community service of Berkshire Botanical Garden, located in Stockbridge, Mass. Its mission, to provide knowledge of gardening and the environment through a diverse range of classes and programs, informs and inspires thousands of students and visitors each year. Thomas Christopher is a volunteer at Berkshire Botanical Garden and is the author or co-author of more than a dozen books.