Cooperative Extension Fact Sheet FS1233 | June 2014
Growing Garlic in the Home Garden
- Phyllis Frederick, Master Gardener, RCE of Middlesex County
- Bill Hlubik, Agricultural Agent, Middlesex County
- Erika Leviant, Master Gardener, RCE of Middlesex County
Garlic (Allium sativum) has had a long and rich history of
both factual and mystical properties. It is one of the oldest cultivated
crops and has been a staple in many diets. Garlic is rich in
antioxidants and beneficial compounds that are considered to have
positive health attributes. One of the best ways to enjoy a variety of
garlic cultivars is to grow your own garlic.
Why Grow Garlic?
Garlic is easy to grow and, if grown properly, has very few pest and
disease problems in the home garden. It requires little space and can be
planted in the fall after many other crops have been harvested.
Hardneck Versus Softneck
Although there are many types of garlic, they can be classified into two broad categories: hardneck (Subspecies: ophioscorodon) and softneck (Subspecies: sativum). As seen in Table 1, each category has several groups with their own characteristics and advantages.
Hardneck garlic is more closely related to wild garlic and typically
has four to twelve cloves around a center flowering stalk. The hardneck
stalk, known as a scape, is topped by a capsule referred to as an umbel
that contains small aerial cloves called bulbils. Hardneck garlic is
more flavorful and the cloves can be peeled from the skin more easily.
The edible hardneck scape provides a milder taste in advance of
harvesting the bulbs. For all these reasons, hardneck garlic is favored
by gourmet chefs.
Softneck garlic does not produce a flower stalk and typically has
more cloves per bulb since all the energy goes to produce the bulb
rather than the bulb and the flower stalk. Softneck garlic is easier to
grow and typically has ten to forty cloves arranged in multiple layers.
It can be braided and generally has a longer shelf life than the
hardneck variety—six to eight months as compared with hardneck's two to
four months. Softneck garlic is more likely to be what you find in the
Table 1: Hardneck vs. Softneck Group Characteristics
(provided with assistance from Leslie Parness, Morris County Park Commission)
|Can be braided
|Uniform size cloves
||Porcelain, Purple Stripe, Rocambole
|Has a scape
||Porcelain, Purple Stripe, Rocambole
||Rocambole, Porcelain, Purple Stripe
||Purple Stripe, Porcelain, Rocambole
|Easiest to grow
There are many cultivars within each garlic group that grow well in
New Jersey. Some examples of hardneck garlic that grow well in our area
are Rocambole cultivars Killarney Red and Spanish Roja, Purple Stripe
cultivars Chesnock Red and Metechi, and Porcelain cultivars Music and
German White. Some examples of softneck garlic that grow well in New
Jersey are Artichoke cultivars Inchellium Red and Lorz Italian and
Silverskin cultivars French Red and Rose Du Var.
Growing garlic takes a bit of patience. For best results, garlic
needs nine months to mature. In New Jersey, it is best planted in
October, (three to eight weeks before the first frost) for a June/July
harvest the following year. Planting stock should be stored at 50°F and
60% relative humidity before planting. Garlic requires a period of cold
followed by a period of light and heat to reach harvestable size.
Select a sunny or partially shady location to plant your garlic. Soil
conditions are important to proper growth and development of the bulbs.
Good soil drainage is essential for good garlic production. One way to
improve the drainage is by creating raised beds before planting. Soil pH
between 6.5 and 7.0 is ideal. Garlic prefers light, well-drained soil
to reduce the number irregularly shaped bulbs. Heavy clay and extremely
light sandy soils can be improved by adding organic matter (i.e.,
compost, peat, or humus) to and mixing thoroughly with the existing
Hardneck Garlic Scape amd Umbel. The Herb Society of America. "Garlic: An Herb Society of America Guide."
Start with healthy, firm, unblemished cloves. In general, the larger
the clove, the larger the resulting bulb. It is recommended to purchase
cloves from a reputable source such as a seed catalog or local garden
center, in order to get named varieties that are disease-free and best
suited for the growing region. Do not use supermarket garlic for
planting stock since they may not grow in this part of the country and
are treated to prevent sprouting. Sample a few varieties to determine
what works best in your garden.
Separate the cloves just before planting by carefully peeling the
outer papery skin and removing the cloves from the base of the bulb,
keeping the individual wrapper (tunic) and scab end (basal plate)
intact. Plant the cloves 1–2 inches deep with the pointed side up. Space
the cloves 3–6 inches apart in rows and 9–24 inches between rows. One
clove will yield one bulb. When planted properly, less density yields
larger, healthier bulbs since it allows for more sunlight and air
Add pesticide-free grass clippings or straw mulch to cover and
protect the planted cloves from winter frost and heaving. A fluffy layer
of fresh grass clippings about three to four inches deep is ideal. The
mulch can be kept in place through the spring to conserve moisture and
suppress weeds. Grass clippings also provide a needed source of nitrogen
as it decomposes. Remove the mulch in the spring, leaving just enough
to suppress weeds.
Garlic requires about an inch of water a week (similar to other garden vegetables) during the spring vegetative growth period.
Garlic can tolerate nutrient poor soil as compared with other garden
vegetables, but benefits from fertile soil with the addition of organic
matter such as compost or aged manure prior to planting. A soil test can
help determine if additional nutrients are necessary. If no soil test
results are available, composted manure may be added prior to planting,
or apply nitrogen (1 lbs/1000 ft2), phosphorus (3–4 lbs/1000 ft2) and potassium (2 lbs/1000 ft2) prior to planting.
In the spring, additional nitrogen (1 lbs/1000 ft2) can be
applied when the plants are 6–8 inches tall. Alternatively, foliar
feeding done every two weeks from mid-March to mid-May may be
beneficial. Feeding works best when applied a day or two after
irrigation or a rainfall. Spray the leaves with a combination of 1–2%
fish solution and .5% kelp.
Stop watering the plants about a month before harvesting (when the
leaves begin to yellow) to keep the papery skin dry and prevent the
bulbs from rotting or splitting.
Weeds are a major concern when growing garlic. Fewer weeds appear in
the spring if the seed bed was properly prepared. Hand hoeing in the
spring as weeds emerge is critical for good garlic production. Start
weeding when the weeds are no more than one inch tall.
Garlic can be harvested in three forms: scapes, green and bulb. In
spring, hardneck garlic produces a scape. There are differing opinions
about whether to cut off the scape. Most growers prefer to remove the
scape to allow the plant to focus its energy on the bulb. The scapes can
be cut off shortly after the flower stalk curls. Harvested scapes can
be used in cooking to provide a garlic tasting green similar to
When garlic is harvested before full maturity, it is referred to as
green garlic. It can be used like green onions in salads or cooking.
Bulbs are ready to harvest when the leaves begin to yellow or brown,
plants start to fall over, and there is still 50% green leaves on the
plant. Green leaves indicate that the bulbs are still intact and have
not begun to break apart.
Harvest bulbs preferably on a sunny, dry day. Do not leave the
freshly harvested bulbs in direct sun for more than a few minutes to
avoid sunburn on the garlic. Softnecks are harvested earlier than
hardnecks since they generally mature faster.
Carefully loosen the soil around the bulbs to minimize damage. The
preference is to dig up the bulbs rather than pull them out. Shake off
the excess soil, keeping the wrapper intact. By having more of the
wrapper intact, the garlic will store longer. Do not wash the bulbs, as
that may encourage the growth of fungus.
Curing and Storing
Curing the harvested garlic will extend the shelf life of the bulb
and strengthen its flavor. To cure, tie the garlic in bunches and hang
in a shady, dry, cool and well-ventilated location for 4–6 weeks. Once
the garlic is dry, trim the roots but retain the outer skin. Brush off
any loose soil and trim the stalks about 1½ inches above the bulb. Store
bulbs for eating at 32°F–35°F with 65–70% relative humidity, such as in
the refrigerator vegetable bin. While garlic may be stored at room
temperature, these temperatures may cause sprouting of the bulbs, so
storage life may be shortened.
Pests and Diseases
Although garlic is less susceptible to insects and diseases than most
vegetative plants due to its natural resistance (primary compound
Allicin), some possible insect problems are onion thrips, onion maggots,
mites, armyworms, and wireworms. Some possible diseases are skin
blotch, white rot, basal rot, pink rot, and viruses.
Insect and disease problems can be minimized by selecting healthy
planting stock, proper growing conditions, adequate crop rotation, and
good sanitation practices. A minimum three-year crop rotation is
advised. Never plant garlic in an area where onion and/or garlic have
recently been grown and always discard, rather than compost, garlic
wrappers and plant materials after harvesting.
- Aaron, Chester. "Garlic: A Growing Guide." Organic Gardening Magazine Online. organicgardening.com/learn-and-grow/garlic-growing-guide. Accessed September 8, 2013.
- Engeland, Ron L. Growing Great Garlic. Okanogan, WA: Filaree Productions, 1991.
- Meredith, Ted Jordan. The Complete Book of Garlic. Portland, OR: Timber Press, 2008.
- The Herb Society of America. "Garlic: An Herb Society of America Guide." herbsociety.org/factsheets/Garlic%20Guide.pdf.
- University of Minnesota Extension. "Vegetable Crop Management, Growing Garlic in Minnesota." extension.umn.edu/distribution/cropsystems/dc7317.html.