Summer days are lawn days, with the hum of mowers in the neighborhood, the scent of grass newly cut, the sight of grounds cloaked in emerald velvet (or blotchy burlap if the owners are lax and the weather dry). For the environmentally minded, these are also days of lawn guilt. Even if we practice sustainable lawn care, eschewing weedkillers and chemical fertilizers, we wonder if these high-maintenance monocultures are justifiable and worth their care.

A large lawn is wasteful. That acreage would be better used to grow food or native vegetation that sustains wildlife. But I’ve made my peace with keeping broad mowed strips of grass between more diverse plantings at our place, as well as a few modest play spaces. We have grandchildren, after all. And there are ways in which lawns contribute to the well-being of our food gardens.

First, although our mowed strips do make a pretty green frame for shrub beds and flower gardens, they also expose scurrying pest rodents such as crop-munching voles to predators such as hawks.

Second, lawns make a contribution to our garden’s fertility because their clippings are compostable. Yes, you can use a composting mower that chops up the clippings so that the lawn itself is fertilized. But if you rake the clippings up, those rich green mounds make great compost fodder, a nitrogen source that reappears weekly to help break down the dry-brown, high-carbon materials in the compost pile. After the dead vines of spring peas are flung on the pile, we spread a layer of fresh grass clippings on top. After perennials are cut back in fall, we do the same.

And third, clippings make a handy mulch. In this case, we let them dry out on the lawn after mowing, then collect them and spread a thin layer — at most an inch — on the vegetable plot as needed. (Since they generate heat during decomposition if used green, it’s especially important to use them dry when mulching small, vulnerable seedlings.) Unlike heavy mulches such as shredded bark or hay, a grass mulch will not keep weeds from coming up, although it will deter some tiny ones. Its main role is to shade the soil surface from the sun. Even that thin layer will decrease evaporation, protect soil organisms and decrease the need for watering. The weeds that do come up will be easier to pull. Think of a grass mulch as sunblock for the soil. It will also provide nutrients to the garden as it breaks down.

Make a point of including clover in your grass seed mix. Some people consider lawn clover a weed, but it’s an attractive green one, and since it’s a legume, it adds fertility to the lawn. (Nodules that form on clover’s roots help make atmospheric nitrogen available to plants.) So turn the lawn into a fertility machine for the garden, put up that volleyball net and let the games begin.

Damrosch is a freelance writer and the author of “The Garden Primer.”