Jennifer Schultz Nelson
Extension Educator, Horticulture
When it comes to garlic, it seems like there are two extremes in people's opinions–they either love it or they hate it. A couple of years ago I was in California with my family, touring the length of the state on the way to my cousin's wedding. During our trip we passed through Gilroy, California, the self-proclaimed "Garlic Capital of the World". Judging by the scent in the air it deserves this title, thanks to a processing plant that turns much of the local crop into jars of minced garlic that make their way into grocery stores nationwide. I love the smell of garlic, but judging by my dad's comment on the "stink" in the air, the car was not making a stop in Gilroy.
Garlic is a member of the genus Allium, which also includes onions, leeks and chives. A garlic plant resembles an onion, with a leafy top and a bulb growing underground. Unlike an onion bulb, which is composed of several layers of tissue that are easily separated, a garlic bulb is divided into individual cloves, which are essentially young bulbs. The clove is how garlic is typically measured when cooking with garlic, and it is also how garlic is planted.
Fall is the perfect time to plant your own crop of garlic. There is an "old wives' tale" that says to plant garlic on the first day of school and harvest it on the last day of school. It turns out this makes sense in light of how garlic grows. Technically you can plant garlic in the very early spring with good yields, but most experts agree that yields are more reliable with a fall planting.
This is because garlic is a cool season plant. While temperatures are cool and days are short, the plant produces leaves. When temperatures rise and days lengthen, this is the signal for the garlic plant to start forming a bulb underground. Typically the tops begin to die back in June, and bulbs are harvested in July. The amount of leaf growth is directly related to the size of bulb produced–more leaves means larger bulbs.
Here in Illinois, where it seems like some years the weather jumps from forty to ninety degrees overnight, spring is only a brief pause along the way to summer. If the garlic plant does not produce enough leaves before hot weather sets in, it will not be able to form a large bulb.
Garlic prefers rich, well-drained soil in a sunny location. It is a good idea to add organic matter and about three pounds of balanced fertilizer per 100 square feet at planting time to encourage good leaf growth and ample bulb formation. Individual garlic cloves are planted about two inches deep and four inches apart.
Many garden centers and mail order catalogs sell garlic bulbs for home gardens. These sources are generally more reliable than trying to use garlic from the grocery store. Remember that the larger the clove, the larger the bulb produced. Typically the outer cloves of a garlic bulb are larger and will produce larger bulbs than the significantly smaller inner cloves.
There are three basic types of garlic grown: softneck, stiffneck, and elephant. Softneck garlic has the strongest flavor and as the name implies, the bulbs have a soft "neck" of tissue. The necks are easily braided into ropes, a common way to store garlic. Stiffneck has a milder flavor than softneck, has a very stiff neck and forms a hard stalk called a scape that has a cluster of bulblets on the tip. The bulblets are edible as is, or can be planted and will form full-sized bulbs in two years. Elephant garlic is in fact not a garlic but a leek that forms a very large bulb with a garlic-like flavor. It has the most mild flavor of all the garlics.
Garlic is believed to have originated in Central Asia. It was used in cooking, but more often was considered a valuable medicine by ancient people. The regions near the Mediterranean Sea and India developed a particular appreciation for garlic. In Egypt it became so revered as a powerful medicine that clay models of garlic were placed in the tomb of Tutankhamen, and was used as a form of currency.
Garlic was the cure-all of the ancient world. The list of ailments it was said to cure was wide and varied–from dog bites to asthma, leporosy, bladder infections or the plague, garlic was the answer. And don't forget legends say that garlic will protect you from vampires and the dreaded Evil Eye. It was also considered a stimulant and insured general vigor besides also being a potent aphrodisiac. The ancient Egyptians are said to have fed garlic to the slaves that built the pyramids to increase their stamina.
As with many "old wives' tales" and legends, there is a shred of truth to the medicinal qualities of garlic. In 1858 Louis Pasteur documented that garlic successfully killed bacteria. During World War II when antibiotics and sulfa drugs were in short supply, a solution of garlic was used to disinfect soldiers' wounds.
One chemical component believed to play a significant role in the antiseptic power of garlic is allicin. This sulfur-containing compound is a major contributor to garlic's pungent flavor and is produced by garlic cells in response to wounding, as when an insect feeds on the plant, or when cloves are crushed for use in cooking.
Allicin has shown promising antimicrobial action. Doctors are particularly excited about recent research which has shown allicin is able to kill the antibiotic resistant bacteria MRSA and VRE which have been the source of life-threatening infections in patients. Unfortunately, allicin is a very unstable compound, and rapidly degrades. Researchers are working to formulate more stable versions of allicin that maintain their antimicrobial power. The goal is to formulate ointments, handwashes and other treatments to prevent patients from contracting MRSA or VRE via wounds or by transmission from health care workers.
Garlic is a great example of modern day science rediscovering and documenting medicinal value in a plant used for centuries in folk remedies. How truly amazing that something as small as a garlic plant can produce compounds effective against microbes that have evaded modern science's best efforts. For me this is one more reason to love and appreciate plants.