Alfalfa contains a wealth of nutrients that have been shown to be beneficial to plant growth. Alfalfa can be used in several forms – meal, cubes or pellets that are broadcast in the garden, or as a tea that is used as a foliar spray or soil drench. Alfalfa is a component of biological gardening.
Alfalfa (Medicago sativa) is a perennial herbaceous legume that grows to about 3-feet in height. It has blue-violet flowers that bloom from July to September. There are species found in the wild all over central Asia and into Siberia. As with other legumes, alfalfa has the ability to ‘fix’ nitrogen in the soil. Because it is known to improve soil structure (tilth) and control weeds in subsequent crops, alfalfa is an integral component of many crop rotation plans.
Alfalfa is classified as a ‘high water usage plant’ because it requires 18 – 36 inches of water per season, but alfalfa is resistant to drought because its roots penetrate deeply into the soil where it can reach all available water. Individual tap roots may reach depths of 20-feet, but the effective depth of feeder roots is approximately 6-feet. It is this characteristic that makes alfalfa so valuable to biological gardeners – the deep roots reach and absorb minerals and nutrients that are not available at the surface.
Alfalfa in history
Remains of alfalfa more than 6000 years old were found in Iran. The oldest writings about alfalfa are from Turkey, dating 1300 B.C. Alfalfa was probably domesticated near Turkmenistan, Iran, Turkey, the Caucasus regions, and other regions in Asia Minor.
Alfalfa was important to the early Babylonian cultures and to the Persians, Greeks, and Romans because of its importance for feeding horses used in war. The Arabs discovered alfalfa in Iran and dubbed the plant the ‘Father of All Foods’. They fed it to their horses claiming it made them swift and strong. The name ‘alfalfa’ comes from Arabic, Persian, and Kashmiri words meaning ‘best horse fodder’ and ‘horse power.’ The modern word alfalfa is derived from the Arabic word alfisfisa, meaning ‘fresh fodder’.
As early as 490 B.C. Roman writers described alfalfa as feed for horses and other domesticated animals. It was introduced into the eastern United States in 1736 and is our oldest introduced forage crop.
Early colonists, including Thomas Jefferson and George Washington, grew alfalfa on a few acres. However, it was not widely grown in this country until the California Gold Rush of 1849. Horses, beef, and milk cows were valuable, and everything was animal-powered. From California, alfalfa spread eastward to Nevada, Utah, Kansas, and Nebraska.
Alfalfa is one of the most nutritious cultivated forage crops in the US. Today, alfalfa is grown on 23 million acres from coast to coast and is the nation’s fourth largest acreage crop.
Out of every livestock feed available, alfalfa produces the greatest amount of protein per acre. It has a very high yield potential compared to other forage crops. It is low in fiber and high in energy when cut prior to early bloom, and is an excellent source of protein, vitamins, and minerals. It is used primarily as a hay crop and is a primary component in dairy cattle rations and feed for horses, beef cattle, sheep, and milk goats.
Alfalfa is so valuable that it is used for human consumption as well. We are all familiar with the alfalfa sprouts used in salads and sandwiches. It is available from health food stores and herbalists in leaf form, capsules, powdered forms and as a tea. It has been combined with dandelion and kelp extracts as a health tonic and is used to treat a number of conditions. As with all herbals, moderation and education should be part of the program.
How it works in the garden
Tests on dry alfalfa reveal that it contains an average of 3.75 –5.5% nitrogen, 0.75 – 3.5% potassium, 0.3 – 0.7% phosphorus, 1 – 2% calcium, 0.30 – 1% magnesium, 0.2 – 0.5% sulfur. Alfalfa also contains important micronutrients – manganese, iron, boron, copper, and zinc – a high concentration of Vitamin A and a number of amino acids. A complete list is available at the end of this article.
In addition to these valuable nutrients, alfalfa contains a powerful growth stimulant – Triacontanol. Triacontanol is a potent plant growth hormone. This naturally occurring stimulant will significantly boost the growth of your plants. In fact, alfalfa has been used as plant stimulant for more than 50 years.
Alfalfa tea will result in superior plant growth and greater bloom production. Plants that are fed alfalfa tea often have a greatly expanded root system over untreated specimens. They may break dormancy earlier and may have a noticeable increase in the thickness and number of leaves.
Daylily and iris growers report a doubling of the number and size of flower buds, flowers and seeds. Orchid and rose growers use alfalfa tea as a foliar spray. Delphinium and hosta growers have found that the Epsom salts included in this brew help to ward off slugs. Vegetable growers report more production by weight, particularly in leafy vegetables. Tomato growers dilute the tea with water 10:1 and use it as a constant drip feed.
Alfalfa supports the growth of beneficial microbes in the soil; particularly beneficial bacteria. Since it is more beneficial to bacteria than to fungi, if you have had problems with an excess of mushrooms or other fungi in your biologically active beds, using alfalfa can diminish their levels somewhat. Alfalfa is inexpensive and can be found at local feed or pet stores. There are advantages and disadvantages to each form available.
Alfalfa meal will breakdown in garden soil more rapidly than pellets or cubes. However, it is very light and dusty. The dust is non-toxic but any dusty material can create respiratory problems if inhaled. Use a mask to cover your nose and mouth when you apply meal, even on a calm day. Stay upwind of prevailing breezes and broadcast it as low as possible to the soil.
Alfalfa pellets are similar to those that are fed to animals such as rabbits. They break down fairly quickly, especially if applied before a rain storm or deep irrigation. The pellets are virtually dust free and can be applied without the alfalfa dust getting into your lungs.
Alfalfa cubes are similar to those fed to stock animals such as cows. Alfalfa cubes are not the best choice for garden use. They are larger than the pellets, making them more difficult to spread across the garden surface evenly. They will take longer to break down.
In general, all dry alfalfa products should be mixed into the soil. This will promote more rapid breakdown making alfalfa’s nutrients and growth stimulant more readily available to your plants.
One word of caution – if you have trouble with wild rabbits, pellets and cubes will only make that problem worse. Mice will also forage on the pellets, but mice seldom forage on your plants. Rabbits, on the other hand, are a destructive garden pest.
Alfalfa tea is a special brew that you can make and apply as a drench directly to your garden soil or use as a foliar spray. Alfalfa tea is the quickest and most effective way to supply alfalfa’s nutrients and growth stimulator to your plants. The tea can be brewed in small batches in a pail or bucket, or can be brewed in quantity in a large drum or trash can. There are several ways to brew alfalfa tea.
Here is one method for a 30-gallon batch:
You will need:
- 32-gallon plastic trash barrel with a fitted lid
- Alfalfa pellets or cubes
- Epsom Salt
- Iron Chelate
- Fish Emulsion
We recommend Brute® by Rubbermaid because these trash barrels are so sturdy. Place the barrel in a convenient location on a flat, sturdy surface. Water weighs 8 pounds per gallon and you will not be able to move it once it is full.
Place 24 cups of alfalfa pellets or cubes in the barrel and fill it with water. Let this sit for 24 hours then stir. Repeat stirring for the next three days to completely dissolve the pellets. If you have used cubes, you may have to stir more than once a day. Keep the lid on tight to prevent mosquitoes from breeding.
The tea will be ready in three days, but you can leave this tea to brew for up to a week. It may begin to bubble. This is just a sign of fermentation and it is not harmful to your product. Your nose will tell you when it is ready since it has a distinct barnyard smell. This is only temporary. If you can stand using fish emulsion on your plants, you can stand using alfalfa tea.
When you are ready to use the tea, add (2) cups of Epsom salt, (3) Tbls of iron chelate and (1) cup of fish emulsion to the barrel and stir thoroughly. Epsom salt is magnesium sulfate which improves nitrogen uptake and increases the production of chlorophyll. Iron chelate is an organic substance that holds micronutrients in a form that can be absorbed by plants. Fish emulsion is a fertilizer made from fish byproducts.
Making smaller batches
Don’t need 30 gallons at a time? Use the ratio of (4) cups of alfalfa to 5 gallons of water. When ready to use, stir in ¼ cup of Epsom salt, (2) Tsp of iron chelate, and (1) Tbls fish emulsion.
Using alfalfa tea
Before applying the tea, put on some old clothes. You may splash a little of the brew onto your clothing. It is not harmful, but it your friends may not want to socialize with you while you are wearing alfalfa tea.
Take a small or convenient size pail and scoop into the tea barrel after stirring one last time and apply to your plants. Apply up to a gallon around a large clump of bulbs or perennials. For smaller clumps, reduce the amount by about one-half.
If you want to use alfalfa tea as a foliar spray, you will need to strain it through several layers of cheesecloth or muslin. An old pillowcase or piece of a bed sheet works well. The solids you strain out can be broadcast in the garden and scratched in.
Apply the tea once per month in the spring and summer. For repeat flowering plants apply after the first flush of flowers to encourage the next flush of blooms.
Stop applying the tea in late August for plants you want to begin hardening off for the winter. Stop applying in early October for all other plants except for winter-blooming annuals.
Reduce or eliminate the Epsom salts in later batches. Epsom salt encourages new canes to break on roses and berries. You do not want to encourage this new growth that could be burned by an early frost.
Alfalfa nutrient information:
* Triacontanol (growth stimulant)
* Vitamin A (high concentration)
* Pantothenic Acid
* Folic Acid
* Crude proteins (16 – 25% in dry alfalfa)
Amino acids (% in alfalfa meal):
* Tryptophan, 0.3 %
* Aspartic Acid, 2.3%
* Threonine, 1.0 %
* Serine, 1.0%
* Glutamic Acid, 2.7%
* Proline, 1.2%
* Glycine, 1.1%
* Alanine, 1.1%
* Cystine, 0.2%
* Valine, 1.0%
* Methionine, 0.3%
* Isoleucine, 0.8%
* Leucine, 1.6%
* Tyrosine, 0.5%
* Phenylalanine, 1.0%
* Histidine, 0.4%
* Lysine, Total, 1.1%
* Arginine, 1.1%
Minerals (contained in dry alfalfa):
* Nitrogen 3.75-5.5 %
* Potassium .75 – 3.5 %
* Phosphorus .3 – .7%
* Calcium 1 – 2 %
* Magnesium .30 – 1 %
* Sulphur .2 – .5 %
* Manganese 30-200 ppm
* Iron 20-250 ppm
* Boron 20-80 ppm
* Copper 5-20 ppm
* Zinc 20-70 ppm