Returning Nutrients to the Soil through Mulch and Cover Crops

The frost came early this year! One night of freezing temperatures in mid-October turned the green leaves of the cucumbers, zucchini, mouse melons, and beans to black. Time for the students to pull out the dead vegetation, put it in the compost bins, and prepare the beds for winter! We were grateful for the bounty that all those veggies provided, and sad to see the end of the season.

As part of putting the farm to bed for the winter, we mulch and plant cover crops.

Students mulched the overwintering kale with grass clippings to prevent the germination of weed seeds, and fertilize the soil when the grass decomposes.

They also spread straw as a “winter blanket” to keep down weeds and prevent pounding winter rains from leaching nutrients from the soil.

In the terraced beds, fourth graders planted a mixture of rye, and the legumes vetch, field peas, red clover, and fava beans as cover crop, and then covered it with compost to help it germinate.

These cover crops prevent weed growth, and sequester nutrients. When the students turn them into the soil in January, the decomposing plants add organic matter to the soil, and nourish the soil food web. The legume cover crops have the bonus of adding nitrogen. Cover crops are called green manures for their effectiveness in adding fertility to the soil. They are a key component of sustainable agriculture that the students are experiencing first hand.


Second graders love using shovels! They chopped in a summer cover crop of buckwheat, so that all its phosphorus-rich organic matter will be available to the spring crops. They also then mulched these beds with straw.

The kindergartners also got in on the cover crop action. They planted field peas, with the bonus that they can eat the pea shoots grazed from the bed, blended into pesto, or chopped into a salad! Kindergarteners also made sure the cover crop seeds were well-watered.

Kindergartners sprinkled field peas as cover crops.

After sprinkling peas over the bed, kindergartners spread compost to cover the peas and provide nutrients to the soil and the cover crop.

Now the winter cycle of soil restoration and regeneration begins.

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