I’ve been thinking a lot about lawns lately. I recently attended a lecture series including a captivating talk from LA-based architect and artist, Fritz Haeg. His book, Edible Estates: Attack on the Front Lawn, has been called “…an ingeniously subversive landscaping manifesto..”(Susan Morgan, The New York Times) and rightly so. His approach to helping people reconnect with the food they eat is not your typical utopian fantasy of moving out to the middle of nowhere and starting over. Instead he urges us to awaken the possibilities of reconnecting with nature and with each other by growing food publicly in the places in which we already are.
Haeg’s lecture followed the structure of his Edible Estates book. He took us on a journey across suburban America as he transformed the front lawns of eight families into edible community gardens. If you don’t know much about the historical and cultural history of the lawn I recommend you check out some of the links at the bottom of this post. It really is a fascinating story. But to sum it up, the idea of the front lawn as a quintessential icon of the "American Dream" eventually grew into a kind of obsession for homeowners who will now go to extreme measures to ensure that nothing infiltrates their pristine lawn environment. Did you know that ~ 40,000 square miles of North America is devoted to lawns (Fulford, 1998)? From this perspective, lawn is the biggest crop in the United States, taking up more space than wheat, corn, or tobacco!
This got me thinking about what we might lose if everyone got rid of their front lawns and replaced them with edible gardens. Besides the inherent value of lawn as a place for leisure and recreation, is there anything worth salvaging in the ideal or the reality of a lawn? What about the lawn that exists in the gray area between the highly-manincured monoculture of grass and the edible community garden in front of every Americans home? The plants that live in these gray areas, between the ‘wild’ and ‘managed’ ideals of our front lawns, are most often a variety of European invasive weeds with a long history of medicinal and culinary uses.
Invasive plants and weeds are the “outlaws” of the plant world. Native plant advocates, ecologists, conservation biologists and many other people shudder at the mention of invasive weeds and some may even go as far as to destroy these plants to restore order and goodness to the world. I’ve seen perfectly sane healthy people, furiously ripping English ivy off a tree, yelling and cursing as they stomp the lifeless vines into oblivion. I’ve watched entire communities band together to dig up huge expanses of Scotch Broom by the roots, piling them up, covering them with kerosene and gleefully watching as they burn the helpless plants alive, oohing and awing at the crackling, popping noises of the legume seed pods bursting, scorching out the possibility of life.
Okay, maybe I’m exaggerating just a little, but it seems strange that we call non-native plants growing in our gardens “food” or even “medicine”, but we reserve the term “weed” for non-native species other than grass that happen to take hold in our front yards.
I know some of you might be thinking this is botanical heresy. Some of you may even have your finger on the ROUND UP trigger, just waiting to exterminate the dandelions growing in your front lawn. Wait! Don’t get me wrong. I’m not suggesting we let these plants take over our neighborhoods and gardens. And of course I don’t think we should ignore the environmental impact and misuse of resources that go into maintaining lawns or the isolation that occurs because of the physical barriers that lawns create between our neighbors and ourselves and between humans and nature.
So what AM I saying? Let’s embrace our weeds and build a garden bed this year especially for them! Let’s appreciate their aesthetic, edible and medicinal qualities!
Check out this Wall Street Journal video with Dr. James Duke showing us around his garden of weeds!
And now, to satiate my phytochemical hunger, I thought it would be fun to profile a few of my favorite European invasive weeds. Since there are so many wonderful web resources that present the traditional and medicinal uses of these plants (see the list at the end of this post), I will be brief in this regard. Instead, I will focus on linking in research on the specific phytochemicals that act synergistically (in my opinion) with the vitamins, minerals and other compounds to create the unique medicinal qualities of each plant. Oh, and remember, some plants are poisonous...ask an expert before eating anything you pick from your yard and I'm not making any claims about health benefits of these plants...disclaimer...blah blah...
Dandelion (Taraxacum officinale) (Asteraceae)
Medicinal uses: diuretic, laxative, cholagogue, anti-rheumatic, anti-inflammatory, choleretic, anti-carcinogenic and hypoglycemic
Plant parts used: leaves and roots
Bioactive constituents: flavonoids, phenolic acids, sesquiterpenes, triterpenoids and inulin
Notes of phytochemical interest: Triterpene alcohols, such as taraxasterol, are found in high concentrations in Taraxacum officinale flowers, as well as many other Asteraceae. These compounds possess strong anti-inflammatory and anti-tumor activities (Takido et al., 1996).
References and further reading fro Dandelion:
Ovesná Z, Vachálková A, Horváthová K. 2004. Taraxasterol and beta-sitosterol: new naturally compounds with chemoprotective/chemopreventive effects. Neoplasma. 51(6), 407-14.
Takido M., Kumaki K., Tamura T. 1996. Triterpene alcohols from the flowers of Compositae and their anti-inflammatory effects. Phytochemistry 43:1255–1260
Schütza, K., Carlea, R. Schieber, A. 2006. Taraxacum—A review on its phytochemical and pharmacological profile. Journal of Ethnopharmacology.107 (3) 313-323.
Chicory, Cichorium intybus (Asteraceae)
Plant parts used: Root, leaves
Bioactive constituents: Chicory is one of the best commercial sources of the compound inulin, the characteristic storage carbohydrate found in the Asteraceae. The chemical structure of inulin (see image below) consists of many fructose units (from 20 up to several thousand) units and sometimes a terminal glucose. When ingested, inulin can be help to regulate diabetes and hypoglycemia because it does not elevate blood sugar levels. This is because inulin is indigestible to humans and does not break down into single sugar units. Other bioactive secondary metabolites include monoterpenes, sesquiterpenes, coumarins, flavonoids and vitamins
Medicinal and edible uses: tonic, laxative, diuretic and many others. Cichory root can be used as a coffee substitute or even to extend coffee, which is a traditional preparation common in New Orleans. Daniel Leyten talks about the process of making Chicory infused coffee and also provides a nice historical description of chicory use in coffee at his blog, New Orleans Cuisine.
Notes of phytochemical interest: Recent studies have provided some insight into the ecological functions of a class of sesquiterpenes lactones known as guaianolides found in Chicory root (Nishimura et al., 2000). These compounds can act as phytoalexins, which are antimicrobial substances produced by plants de novo in response to attack by pests or pathogens and accumulate rapidly at the site of wounding. For example, the guaianolide found in Chicory called, cichoralexin, possesses strong antimicrobial and nematicidal activities (Nandagopal and Kumari, 2007). This research is being applied to the preservation of processed foods where the addition of dry powder from Chicory rhizomes extends the shelf life.
References and further reading for Chicory:
Bais H.P., Ravishankar, G.A. 2001.Cichorium intybus L – cultivation, processing, utility, value addition and biotechnology, with an emphasis on current status and future prospects. Journal of the Science of Food and Agriculture. 81(5) 467-484.
Nandagopal, S. and B.D. Ranjitha Kumari. 2007. Phytochemical and Antibacterial Studies of Chicory (Cichorium intybus L.) - A Multipurpose Medicinal Plant Advances in Biological Research 1 (1-2): 17-21.
Nishimura H.; Kondo Y.; Nagasaka T.; Satoh A. 2000. Allelochemicals in Chicory and Utilization in Processed Foods. Journal of Chemical Ecology. 26 (9) pgs 2233-2241.
Red Clover, Trifolium pratense (Fabaceae)
Plant parts used: flowerheads
Medicinal use: expectorant, analgesic, antiseptic properties, rheumatic aches, treatment of skin conditions such as eczema and psoriasis
Bioactive constituents: isoflavones (phytoestrogens), coumarins, saponins
Notes of phytochemical interest: The isoflavone constituents in red clover, in particular, daidzein, genistein, formononetin (shown on left), and biochanin, can act as phytoestrogens in vivo and are currently in Phase II clinical trials for the treatment of hot flashes in menopausal women (Booth et al. 2006).
References and further reading fro Red Clover:
Booth, N. L., Overk, C.R., Yao,P. Burdette, J. E., Nikolic, D., Chen, S. N., Bolton, J. L., van-Breemen, R. B., Pauli, G. F., Farnsworth, N. R. 2006. The chemical and biological profile of a red clover (Trifolium pratense L.) phase II clinical extract. J-Altern-. Complement-Med. 12 (2) 133-9.
Sabudak T, Guler N. (2009). Trifolium L.- A review on its phytochemical and pharmacological profile. Phytother Res 23: 439–446
Plantain (Plantago major) Plantaginaceae
Plant parts used: leaves and aerial parts
Medicinal uses: expectorant, demulcent, astringent and diuretic, anti-inflammatory, wound healing
Bioactive constituents: flavonoids, triterpenoids, irodoid glycosides
Notes of phytochemical interest: One of the most fascinating qualities of Plantain, Plantago major (Plantaginaceae family) is its ability to effectively heal wounds. A. B. Samuelsenin outlines the historical use of Plantain as a wound healer in his review article on ethnobotany and phytochemistry of Plantago major (2001). He describes:
“The traditional use of P. major in wound healing is quite old. It was described by the Greek physician Dioscorides in ‘De materia medica’ in the first century. The leaves were prescribed for treatment of dog bites (Roca-Garcia, 1972). From the ‘Vølsuga saga’ it is known that the Vikings used P. major leaves for wound healing (Nielsen,1969). P. major was also described in the 12–13thcentury by the Islamic author Ibn El Beithar having adopted the knowledge from Greek medicine (Fleurentin et al., 1983). Henrik Harpestreng († 1244) from Denmark wrote in ‘Liber Harbarum’ that P. major could heal everything that was torn apart. Mixed with honey it was recommended on wounds. Boiled with butter and eaten, it could heal any organ in the human body (Nielsen, 1969).”
He goes on to explain that despite intensive research into the bioactive constituents of Plantago major, the actual mechanisms underlying its wound healing properties are still a bit of a mystery:
“There are several of the isolated compounds that may aid the healing of wounds. Plantamajoside and acteoside have antibacterial activities. Some flavonoids and the caffeic acid derivatives plantamajoside and acteoside have antioxidative and free radical scavenging activities. Pectic polysaccharides have been reported to be effective against ulcers in rats and for having immunostimulatory activities. Finally, the long chained saturated primary alcohols that are present in the leaf wax aid the healing of superficial wounds. However, the leaves also contain compounds with anti-inflammatory activity, namely plantamajoside, baicalein, hispidulin, aucubin, ursolic acid and oleanolic acid. Since the inflammatory phase in general is necessary in the wound healing process, anti-inflammatory activity may be undesirable. On the other hand, these substances’ activities when acting together with other compounds present in the leaves are not known at present. Thus, the full picture of P. major as a wound healing remedy may be rather intricate.”
References and further reading for Plantain:
Ringbom T, Segura L, Noreen Y, et al. 1998. Ursolic acid from Plantago major, a selective inhibitor of cyclooxygenase-2 catalyzed prostaglandin biosynthesis. Journal of natural products. 61 (10) 1212 -1215.
Samuelsen, A. B. 2001. The traditional uses, chemical constituents and biological activities of Plantago major L. A Review. Journal of Ethnopharmacology. 71, 1-21.
Turel I, Ozbek H, Erten R, et al. Hepatoprotective and anti-inflammatory activities of Plantago major L. 2009. Indian Journal of Pharmacology. 41(3) 120-124.
For more information on the traditional uses of these medicinal plants:
A Modern Herbal by Mrs. M. Greive
Plants for a Future: A Resource and Information Centre for Edible and other useful plants
Dr. Duke’s Phytochemical and Ethnobotanical Database
Michael Moore’s Southwest School of Botanical Medicine
More on Weed-loving lawns and gardens:
Here's a great article on Edible Lawns.
Weeds in your Garden? Bite Back! By Susan Weed
Making dandelions palatable. By John Kalllus, Ph.D.
History of "the Lawn":
History of Lawns in America
Photo credits: Dandelion head: Ted Kropiewnicki, Monticello lawn: Matt Kozlowski Monticello, Chicory: Anders Bjurnemark, Inulin structure: Florian Fisch, Line drawing of Red Clover: Lalita Calabria