5 Cover Crops Good For Your Health And The Soil

When you take care of your soil by planting a cover crop, don’t overlook the medicine hiding in these plants.

by Dawn Combs
PHOTO: SARE Outreach/Flickr

When we think of carbon emissions, land management typically isn’t the first thing that comes to mind. In The Soil Will Save Us (Rodale, 2014), author Kristin Ohlson writes that the imprudent ways we manage agricultural land accounts for 30 percent of the world’s carbon emissions. Rattan Lal, director of the Carbon Management and Sequestration Center at The Ohio State University in Columbus, Ohio, believes that if we were to change the way we work the soil, we could amass carbon at our feet and take 3 billion tons of carbon out of the atmosphere each year.

The idea that we can keep carbon in the soil where it belongs is stunning in an age where we tend to talk about carbon emissions and greenhouse gases mainly when speaking about cars and cows. I grew up with the idea that bare ground in the garden was a normal part of the growing cycle. There is wisdom in keeping our soils covered that goes beyond carbon emissions. Nature shows us that it prefers a blanket.

I see it in action every year when I till the land and don’t get a ground cover down: Weeds of all shapes and sizes creep in to hold the soil in place above and below the soil line. On my farm, these weeds aren’t too much of a bother, and many times, they are plants I might otherwise have desired to plant for their medicinal and edible benefits. Weeding becomes more about harvesting than it is about removing undesirables.

In this country alone, natural supplements are a billion-dollar industry, and I am confident that money could be better spent revitalizing our local communities than enriching large corporations a world away. While a self-sufficient consumer is important, a community is not built on them alone. Farmers and gardeners are at the base of the chain, with only the health of the soil coming before them in importance of the idea of local health.

We can wait, of course, for large sections of our population to be educated in the ways of using plants to support health. Some of those educated will become interested in growing and begin the arduous process of learning to farm, but this will take too long: We already have a system in place for growing the plants we need. The farmers that are currently growing for niche markets or who are interested in a creative way to augment their income are our best hope.

Whether conventional, organic or biodynamic, there are still farmers and gardeners out there that know their soil. You see them in the early spring, truck pulled off in the ditch, squatting in last year’s furrows with a handful of dirt to their noses. These farmers know the value of soil health, they know how to read the weather, and they understand the fickle nature of, well, nature. Many of these farmers already use cover crops to hold moisture, reduce erosion, increase biomass and fix nutrition and those that do are aware that they can spend copious amounts of money to truck in fertilizer or they can grow it themselves; they usually opt for the latter.

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Farmers that use cover crops consider the field that lies fallow under oats or clover to be an investment in their future. They spend the money for the green manure and work other land for an immediate profit.

Eco Meets Economical

What if I could tell you that the investment in fertility for next year could also provide income for this year? Cover crops are the basis of some of our best-loved daily health supplements. If we grow them for the health of the soil and harvest them for human health, it’s a win-win for everyone.

Perhaps providing an immediate way to profit from planting these soil enrichers would encourage more people to rest their fields in this way. Perhaps re-establishing our local health economies could also re-establish soil health, reducing carbon in our atmosphere, improving the food we eat and enriching our lives on a grander scale.

Here are a few common cover crops that demonstrate this dual purpose.

1. Alfalfa

Lotus Johnson/Flickr

Alfalfa (Medicago sativa) is in the Fabaceae family, and when grown as a cover crop, it fixes up to 200 pounds of nitrogen per acre, according to Richo Cech, owner of Strictly Medicinal Seeds, a seed-saving farm and business in Williams, Ore. Alfalfa also has the potential to add 10 tons of organic matter per acre, increasing the soil’s ability to retain moisture and reducing the occurrence of erosion. It’s hardy just about anywhere in the U.S., which means this is a viable option for nearly all of us. It can be cut several times in a growing season, and this is where it becomes interesting.

Growing a stand of alfalfa in the field can improve the soil, provide fodder for animals and give you a crop for your local health community. If your area is just beginning to look for plant-based medicinals, perhaps you take just one cutting and dry it for this purpose. Alfalfa is highly nutritious—a fact we have long exploited in feeding our animals. It is a good source of protein, beta-carotene, and vitamins B and C. On our farm, we use it as part of our vitamin tea that features a variety of plants high in vitamins and minerals, but it has a long tradition of being used for arthritis, ulcers, high cholesterol and high blood sugar levels, and as a digestive aid. As a medicinal, alfalfa is sold dry, mainly for tea.

2. Oats

milky oats

Oats (Avena sativa) are already fairly multipurpose, but there is more we can do with them. When planted as a cover crop, they can help prevent erosion and add biomass to the soil. Oats are often used as nurse crops, meaning they’re planted first and, after germination, another crop is planted under their protective shade. Cover crops in the pea family, such as alfalfa, are commonly planted with oats in this fashion.

All parts of the oat plant are useful to humans, and they’re high in minerals, namely calcium, chromium, magnesium, silicon, sodium, and vitamins A and B. Let the field grow to the point that the oats are “milky,” meaning that when you squeeze the undeveloped oat heads, they exude a milky substance; this is probably somewhere around 35 days. (In the herb trade, we call these milky oats or oat tops.) The plant should be cut about a foot above the ground. This leaves plenty of biomass still standing that can be tilled in for the benefit of the soil.

With the harvested oats, you have two products: The tops can be cut off before or after drying and sold as is, and the stalk that is left can be cut and sold as oat straw. Both of these products are exclusively sold dry. Oats are not a food-as-medicine item unless they are dried in the field and ­processed for oatmeal.

Oat tops are particularly nourishing for the nervous system and are often used for nervous debility and for their ability to soothe our nerve endings. Oat straw has long been used to support the deficiencies that come from poor calcium absorption. Both of these products are helpful in menstrual disorders, osteoporosis and general nervous system imbalances.

3. Red Clover

red clover

Red clover (Trifolium pratense) is a traditional forage crop and is capable of fixing 140 pounds of nitrogen per acre. It’s one of our finest soil re-mediators, but it, too, is dependent on particular soil conditions. Before red clover can begin to do its work, it requires rhizobia, a specific strain of soil bacteria, to be present.

If you have previously worked the land where you would like to grow red clover, you may not need to inoculate your seeds. However, if your soil has been heavily fertilized with chemical fertilizers or if this is a brand-new garden made out of lawn or grassland, you will have a faster and more successful crop if you buy an inoculant when you make your order.

Red clover is high in calcium, magnesium, chromium, phosphorus, potas­sium, tin, and vitamins B and C. All parts of the plant are used when we cut it for fodder, but in food and medicine, we typically only use the flower and the first few leaves, as the leaves can be hard on digestion and cause bloating.

Red clover flowers are well-known in a class of alterative herbs, herbs said to restore function back to the body, purify blood, increase appetite, improve digestion and eliminate toxins. These plants support the health of the liver, often thinning or assisting in the filtering of our blood. They also have a few things to offer for lung and kidney health before we even get to the folkloric uses against various tumors and irregular growths. Red clover is typically sold as a dried herb.

4. Fenugreek


While it may be surprising to use a plant that looks similar to dill as a cover crop, fenugreek (Trigonella foenum-­graecum) has a long tradition as such. Commonly called Greek hay, grazing cattle particularly enjoy fenugreek’s flavor, and it’s often added to hay for that reason.

Fenugreek is an annual in the Midwest, but that’s not really a problem, as the seed is what you’re after, and allowing the plant to develop in a field all season long will get you the soil and medicinal benefits you desire. Fenugreek is primarily used in soil to break up heavy clay and add nitrogen and organic matter. As an added bonus, the airy umbels attract pollinators, so plant it near other crops.

Medicinally, fenugreek has a history that extends back to the ancient world. It was prevalent in Greek, Roman and Egyptian societies. The seed has a high volatile oil content, making it very valuable in digestive tract, respiratory and urinary system ailments. The oils found within the plant are antimicrobial and antispasmodic, which make them very useful in cold and cough formulas. Fresh seed may be sold in a local setting, with a need to dry it for shipping or storage.

5. Sunflowers

Marcel Sigg/Flickr

One of my favorite memories from visiting family in North Dakota is standing on the top of a grain silo, looking over miles of sunflowers (Helianthus annuus) in bloom. There, the sunflower was being grown as a crop, but this beautiful multitasker can also be used as a soil conditioner and can increase the organic content and water holding capacity of your soil. It’s often interplanted with red clover.

Growing sunflower as a cover crop can also provide you with products for the food and medicine community around you. Sunflower seeds are a good source of protein, potassium, iron, phosphorus, calcium, iodine, magnesium, and vitamins B, C and E. They are useful in supporting the reproductive system with a strong emphasis on thyroid and prostate health. Sunflower seeds are often made into a tea and used for a variety of respiratory ailments and fever. Sunflower petals are used in much the same way, and there is an increasing interest in the herbal industry in this beautiful dried flower. Sunflower petals and seeds will need to be dried for sale.

There are many more plants that can benefit the soil while providing you with a viable crop. Simply allowing some of the plants we call weeds to work the land while it lies fallow can often yield surprising results. Allowing the plants to do the work means that soils heal rather than continually needing us to apply nutrition as a bandage.

At the root of any healthy community is healthy soil. It translates to cleaner water and nutrient dense vegetables. I propose now we’re ready to think about how methods to improve the soil might allow us to provide for our family’s table, enrich our soils and provide products for a growing health-care crisis that only a return to local health economies can stem.

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