We often think of herbs for their culinary & medicinal values. But through nutrient accumulation and phyto-remediation, here are nine herbs to improve your soil!
I have been long prodded to write a post on medicinal herbs to improve your soil. As an herbalist and homesteader/farmer, it’s up my alley, right? The reality of it is that the subject is more of a book than a blog post. And truth being told, I am barely scratching the surface here. You can use herbs to improve your soil in very profound ways.
You see, nature has a way of healing itself. Given time, plants repopulate even the most industrial, barren wastelands – pushing up through layers of concrete and metal. Even opportunistic, non-native, invasive species have their place, controlling soil erosion, stabilizing the earth and creating new ecosystems. Alas the subject of invasive plant eradication versus acceptance is another post for another time. Still yet, other botanicals return vital nutrients to the soil, enriching the land for future crops. Using herbs to improve your soil is not only for the land you are tending to, but benefits the entire surrounding eco-system.
Today we discuss a few medicinal herbs in a new light. One that is less about what these herbs do for us, but what they do for the environment. Here is a snapshot look as common medicinal herbs to improve your soil via phyto-remediation and nutrient accumulation.
Medicinal Herbs to Improve Your Soil
(Medicago sativa): While many of us know this medicinal herb as a feed for livestock or the sprouts for our sandwiches and salads, alfalfa is a highly nutritive herb with a host of therapeutic actions. As it applies to soil health, alfalfa is an excellent choice for a variety of reasons. Long lasting foliage and a complex root system prevents soil erosion due to wind and/or water run-off. Alfalfa is an exceptional choice to crop in “buffer zones” such as that near dairy lagoons as the bacteria present in the plants root habitat can make use of excessive nitrogen before it contaminates nearby waterways. On a related note, this crop also fixates nitrogen into the soil, making it an excellent choice for crop rotation as future crops requiring higher nitrogen needs will benefit from alfalfa’s residual inputs.
Learn more about alfalfa garden benefits from Learning & Yearning here.
(Calendula officinalis): A favorite of the herbal apothecary, calendula is the salve for almost any wound. It is also a strong bio accumulator of cadmium. The element is a common environmental pollutant observed in industrial waste. Cadmium disrupts water uptake in sensitive plants and can cause extensive kidney damage in animals and humans.
Make an amazing calendula salve here.
(Symphytum officinale): Often known for its ability to “knit” bone and skin back together, comfrey is a gardener’s dream. Comfrey is considered a guild plant for fruit orchards. Its taproot can grow up to ten feet in length, mining the deep subsoil for minerals and moisture, making it a prime choice for reducing evaporative moisture losses from the soil. At the end of each growing cycle, this perennial will back to the ground leaving a nutrient dense mulch in its place.
Learn more about making a comfrey tea liquid fertilizer from Grow Forage Cook Ferment here.
(Althea rosea): This showy cousin to marshmallow and member of the Malvaceae family, is more that just a cottage garden favorite with cooling, soothing medicinal benefits. Hollyhocks are credited with the uptake of excessive copper from soils.
(Verbascum thapsus): Mullein is often one of the first wild plants to re-establish contaminated and industrial areas after abandonment. This respiratory plant ally is also a vital part of the Earth’s natural waste clean up areas. Mullein has been identified as another hyper accumulator of cadmium.
More on the medicinal benefits of mullein can be seen here.
(Avena sativa): We all love oats for their nutritional and medicinal benefits. Oats are an ideal cover crop, sown in the fall. The extensive root system of oats secures the tops soil preventing erosion and run-off due to flooding. Oats also accumulate calcium from the soil; composted oatstraw worked back into the soil serves to “sweeten” the dirt in acidic areas.
Check out information on growing oats here.
(Trifolium pratense): Red clover hits all the marks as a medicinal, nutritional and cover crop. This pretty legume is a “nitrogen fixer”. It is the perfect crop to add to a rotation where soils are notoriously nutrient poor, conditioning the soil and preparing into for future crops with heavier nutritional needs. It also attracts pollinators, to the great benefit of neighboring plants!
Try this yummy red clover jam!
(Salix species): This pain-relieving botanical of the Populus family is a choice shrub for maintaining soil integrity in riparian areas. It is also an excellent bio-remediator of some heavy metals from the soils including cadmium and zinc, as well as copper and lead, to a lesser extent.
Make some willow rooting hormone with Attainable Sustainable here.
(Achillea millefolium): Yarrow is a must in every apothecary and garden. Yarrow is thought to increase the essential oil yield of neighboring plants (usually helping to deter pests). Left to die back to the ground each fall/winter or transfer to the compost heap, yarrow is considered a “compost activator” in the bio dynamic farming tradition, adding valuable nutrients, especially nitrogen.
Yarrow has a ton of medicinal benefits. Learn more here.
How to handle plants used for nutrient accumulation
Herbs that add nutrients to the soil should be left to die back into the dirt, then worked into the soils after sufficient decomposition. For a “tidier” appearance, one can remove trimmings to a compost heap and spread into the garden and planting beds when the compost is well rotted and rich.
How to handle plants used in phyto-remediation
Bio-remediation presents so challenges when it comes to actually removing the contaminants permanently from an area. Plants used in bio-remediation efforts should not be used for nutritional or medicinal purposes and should not be left to die back into the soil or added to the compost heap. Bio-remediation researchers suggest incineration or gasifying contaminated plants. This can not be done effectively in the home. Call your local county extension office or waste management company/waste station to discuss best disposal methods for your location.
This list of herbs to improve your soil includes nutrient accumulators and phyto-remediators is by no means comprehensive. I mean this post as encouragement to explore the wide variety of plants that not only benefit humans, but offer healing and nutrition to the land that we rely on!
Looking for more ways to improve your soil. Consider the “lasanga gardening” method explained in this post from Learning and Yearning.
Learn about 50 common medicinal herbs with my new book, The Backyard Herbal Apothecary.
This is a very interesting article and subject that I have recently become interested in. Are there any books or websites that you would recommend to further my knowledge on this topic?
Once upon a time I had all my source cited in this post, but appear to have accidentally deleted that while moving text and photos around. I like to look for more scholarly research type papers on Google Scholar and from universities when searching “phyto-remediation” and “bio-accumulation”.