Alfalfa, Yellow alfalfa
Medicago sativa
Family: Fabaceae or Leguminosae
What it is like
Medicago sativa is a PERENNIAL growing to 1 m (3ft 3in) at a medium rate. See above for USDA hardiness. It is hardy to UK zone 5. It is in flower from June to July, and the seeds ripen from July to September. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees, Lepidoptera (Moths & Butterflies). The plant is self-fertile. It can fix Nitrogen. It is noted for attracting wildlife. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It cannot grow in the shade. It prefers dry or moist soil and can tolerate drought.
Height (m): 1
Where it is found
Waste ground, avoiding acid soils.
Europe - Mediterranean. More or less naturalized in Britain.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 4
Leaves and young shoots - raw or cooked. The leaves can also be dried for later use. Very rich in vitamins, especially A, B and C, they are also a good source of protein. The leaves are a rich source of vitamin K. A very nutritious food in moderation, though it can trigger attacks in patients with systemic lupus erythematosus and large quantities can affect liver function and cause photosensitization. A nutritional analysis is available. The seed is commonly used as a sprouted seed which is added to salads, used in sandwiches etc or cooked in soups. The seed is soaked in warm water for 12 hours, then kept moist in a container in a warm place to sprout. It is ready in about 4 - 6 days. The seeds can also be ground into a powder and used as a mush, or mixed with cereal flours for making a nutritionally improved bread etc. Seed yields average around 186 - 280 kilos per hectare. An appetite-stimulating tea is made from the leaves, it has a flavour somewhat reminiscent of boiled socks and is slightly laxative.
Oil: Oil
Seed: includes nuts, cereals, peas and beans.
Tea: the various herb teas that can be used in place of tea, plus the genuine article.
Medicine
Rating: 3
Alfalfa leaves, either fresh or dried, have traditionally been used as a nutritive tonic to stimulate the appetite and promote weight gain. The plant has an oestrogenic action and could prove useful in treating problems related to menstruation and the menopause. Some caution is advised in the use of this plant, however. It should not be prescribed to people with auto-immune diseases such as rheumatoid arthritis. See also the notes above on toxicity. The plant is antiscorbutic, aperient, diuretic, oxytocic, haemostatic, nutritive, stimulant and tonic. The expressed juice is emetic and is also anodyne in the treatment of gravel. The plant is taken internally for debility in convalescence or anaemia, haemorrhage, menopausal complaints, pre-menstrual tension, fibroids etc. A poultice of the heated leaves has been applied to the ear in the treatment of earache. The leaves can be used fresh or dried. The leaves are rich in vitamin K which is used medicinally to encourage the clotting of blood. This is valuable in the treatment of jaundice. The plant is grown commercially as a source of chlorophyll and carotene, both of which have proven health benefits. The leaves also contain the anti-oxidant tricin. The root is febrifuge and is also prescribed in cases of highly coloured urine. Extracts of the plant are antibacterial. Used for asthma, diabetes, gastrointestinal disorders (anti-ulcer) .
Anodyne: Relieves pain, it is milder than an analgesic.
Antibacterial: Kills bacteria.
Antiscorbutic: A plant rich in vitamin C that is used to counteract scurvy.
Aperient: A mild laxative.
Diuretic: Acts on the kidneys, promoting the flow of urine.
Emetic: Induces vomiting.
Febrifuge: Reduces fevers.
Haemostatic: Controls internal bleeding.
Hypoglycaemic: Reduces the levels of sugar in the blood.
Nutritive: A food for convalescents to help restore strength.
Stimulant: Excites or quickens activity of the physiological processes. Faster acting than a tonic but differing from a narcotic in that it does not give a false sense of well-being.
Tonic: Improves general health. Slower acting than a stimulant, it brings steady improvement.
Other
Rating: 4
Often grown as a green manure. It is a bit slow to establish in its first year so is generally only recommended for positions where it can remain for 2 or more years. Alfalfa is very vigorous from its second year, producing a huge bulk of material that can be cut down 2 or 3 times during the season. Plants are very deep rooting, descending 6 metres or more into the soil, and are able to fix large quantities of atmospheric nitrogen, this makes them one of the very best green manures. Plants are rather intolerant of competition from grass etc, however, and there is the drawback of needing to leave them in the soil for more than 2 years to fully achieve their potential. Alfalfa is a potenially excellent source of biomass. It is possible to produce more than 2 tonnes of protein from the leaves (suitable for human use) per hectare per year. In addition, the plant residues remaining could be used to produce the equivalent of about 10 barrels of oil per year. A yellow dye is obtained from the seed. The fibre of the plant has been used in making paper. The seed yields about 8.5 - 11% of a drying oil. It is used in paints, varnish etc. The plant can be grown as a low dividing hedge in the vegetable garden. A dynamic accumulator gathering minerals or nutrients from the soil and storing them in a more bioavailable form - used as fertilizer or to improve mulch.
Biomass: Provides a large quantity of plant material that can be converted into fuel etc.
Companion: Companion planting is the careful placement of plants (especially vegetables and herbs) which have been shown to have beneficial effects on one another.
Dye: Plants that provide dyes.
Green manure: Fast-growing plants that can be used to increase the fertility of the soil.
Hedge: Plants that can be grown as hedges.
Oil: Vegetable oils have many uses, as lubricants, lighting, soap and paint making, waterproofing etc. This does not include the edible oils unless they are also mentioned as having other uses.
Paper: Related to the entry for Fibre, these plants have been specifically mentioned for paper making.
Global Crop: These crops are already grown or traded around the world. The annual value of each is more than $1 billion US Examples include coconuts, almonds, and bananas.
Management: Hay: Cut to the ground and harvested annually. Non-destructive management systems maintaining the soil organic carbon.
Staple Crop: Protein: (16+ percent protein, 0-15 percent oil). Annuals include beans, chickpeas, lentils, cowpeas, and pigeon peas. Perennials include perennial beans, nuts, leaf protein concentrates, and edible milks.
Global Crop: These crops are already grown or traded around the world. The annual value of each is more than $1 billion US Examples include coconuts, almonds, and bananas.
Management: Hay: Cut to the ground and harvested annually. Non-destructive management systems maintaining the soil organic carbon.
Staple Crop: Protein: (16+ percent protein, 0-15 percent oil). Annuals include beans, chickpeas, lentils, cowpeas, and pigeon peas. Perennials include perennial beans, nuts, leaf protein concentrates, and edible milks.
Attracts Wildlife: Plants noted for attracting wildlife
Carbon Farming: Plants that can be a critical part of the solution to climate problems. The Carbon Farming Solution - Eric Toensmeier.
Dynamic accumulator: Plants that gather minerals or nutrients from the soil and store them in a more bioavailable form and in high concentration in their tissues. Used as fertilizer or to improve mulch.
Food Forest: Plants for Edible Forest Gardens and Food Forests.
Hedge: Hedge
Nitrogen Fixer: Plants that fix nitrogen in the soil
How it is grown
Alfalfa is a very versatile plant that can adapt to a wide range of climatic conditions from cold temperate to warm sub-tropical.. It succeeds on a wide variety of soils, but thrives best on a rich, friable, well-drained loamy soil with loose topsoil supplied with lime. It does not tolerate waterlogging and fails to grow on acid soils. Grows well on light soils. The plant has a deep taproot and, once establishd, tolerates drought and extremely dry conditions. Prefers a neutral fertile soil but succeeds in relatively poor soils so long as the appropriate Rhizobium bacteria is present. A good bee plant and a food plant for many caterpillars. Alfalfa is a very deep rooting plant, bringing up nutrients from deep in the soil and making them available for other plants with shallower root systems. It is a good companion plant for growing near fruit trees and grape vines so long as it is in a reasonably sunny position, but it does not grow well with onions or other members of the Allium genus. Growing alfalfa encourages the growth of dandelions. Alfalfa has long been cultivated for its edible seed, which can be sprouted and eaten in salads. It is also grown as a green manure and soil restorer. There are many named varieties. Botanists divide the species into a number of sub-species - these are briefly described below: M. sativa caerulea (Less. ex Ledeb.)Schmalh. This sub-species is likely to be of value in breeding programmes for giving cold tolerance, drought resistance and salt tolerance to alfalfa. M. sativa falcata (L.)Arcang. This sub-species is likely to be of value in breeding programmes for giving cold tolerance, drought and disease resistance plus salt and water-logging tolerance to alfalfa. M. sativa sativa. The commonly cultivated form of alfalfa. M. sativa varia (Martyn.)Arcang. This sub-species is likely to be of value in breeding programmes for giving cold tolerance, drought resistance and high yields to alfalfa. This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby. The plant is heat tolerant in zones 8 through 5. (Plant Hardiness Zones show how well plants withstand cold winter temperatures. Plant Heat Zones show when plants would start suffering from the heat. The Plant Heat Zone map is based on the number of "heat days" experienced in a given area where the temperature climbs to over 86 degrees F (30°C). At this temperature, many plants begin to suffer physiological damage. Heat Zones range from 1 (no heat days) to 12 (210 or more heat days). For example Heat Zone. 11-1 indicates that the plant is heat tolerant in zones 11 through 1.) For polyculture design as well as the above-ground architecture (form - tree, shrub etc. and size shown above) information on the habit and root pattern is also useful and given here if available. The plant growth habit is a clumper with limited spread. The root pattern is a tap root similar to a carrot going directly down.
Propagating it: Pre-soak the seed for 12 hours in warm water and then sow in spring in situ. The seed can also be sown in situ in autumn. Seed can be obtained that has been inoculated with Rhizobium bacteria, enabling the plant to succeed in soils where the bacteria is not already present.
Best place to grow: Hedge; Cultivated Beds;
Habit: Perennial
Hardiness: 4-8
Growth: Medium
Soil: Light (sandy), medium, heavy (clay)
Shade: No shade
Moisture: Dry, moist
Things to keep in mind
The plant contains saponin-like substances. Eating large quantities of the leaves may cause the breakdown of red blood cells. However, although they are potentially harmful, saponins are poorly absorbed by the human body and so most pass through without harm. Saponins are quite bitter and can be found in many common foods such as some beans. Thorough cooking, and perhaps changing the cooking water once, will normally remove most of them from the food. Saponins are much more toxic to some creatures, such as fish, and hunting tribes have traditionally put large quantities of them in streams, lakes etc in order to stupefy or kill the fish. Alfalfa sprouts (and especially the seeds) contain canavanine. Recent reports suggest that ingestion of this substance can cause the recurrence of systemic lupus erythematosus (an ulcerous disease of the skin) in patients where the disease had become dormant. The FDA advises that children, the elderly and people with compromised immune systems should avoid eating alfalfa sprouts due to bacterial contamination. Avoid during pregnancy and lactation. Avoid for people with hormone sensitive cancer. Avoid for people with gout (due to purines). Possible antagonize the anticoagulant effect of warfarin (due to vit K) and interfere with the immunosuppressant effect of corticosteroids .