Growing Garlic in the Garden
Updated: Feb 15
In this Article, I Provide A Fearless Guide On Growing Garlic in the Garden. This is for First Time Garlic Growers, or Growers who are Looking for More Knowledge.
GARLIC. AN OVERVIEW
Garlic (Allium sativum) is a species of plant in the genus Allium. Its close relatives include the onion, shallot, leek, and chive. The word garlic derives from Old English, garlēac, meaning gar (spear), and leek, as a 'spear-shaped leek'. Garlic is a perennial that grows best in loose, fertile soil, in full sun exposure. Garlic is considered a perennial - perennials are plants that persist for many growing seasons. A mature garlic plant produces a rounded bulb beneath the soil, and this bulb is covered with membranous skin and encloses the edible bulblets called cloves. The mature plant has long, sword-shaped leaves. Garlic contains diverse bioactive compounds, such as allicin, alliin, diallyl sulfide, diallyl disulfide, diallyl trisulfide, ajoene, and S-allyl-cysteine. When raw garlic cloves are crushed, chopped, or chewed, an enzyme known as alliinase is released. The biological properties of garlic have been extensively studied. Garlic has been associated with immune-enhancing, antibacterial, antifungal, antiviral, and anticancer functions. Garlic is typically grown for seed and for use as a spice. If someone acquires porcelain garlic such as the Rosewood cultivar, seed garlic, and culinary garlic are genetically identical; Larger garlic cloves are used as seed, because they have more stored energy. Smaller garlic is often sold for culinary purposes. Large garlic cloves can also be used for culinary and are excellent for roasting and for making black garlic (Black garlic is aged fresh garlic with a smooth, soft texture and a rich, sweet taste. Think Garlic Gummy Bear)!
GROCERY STORE GARLIC
Much of the garlic observed in grocery stores is the softneck variety, grown in warmer climates such as China and California. Elephant garlic, also grown in warmer climates, is not a true garlic and is closely related to leeks. It is common for gardeners to plant garlic that they acquired from the grocery store. Likely they were disappointed with the results and small bulbs. Grocery store garlic is often in poor condition and likely has been in storage for a long time. Grocery store garlic is often sprayed with chemicals to prevent or delay sprouting and reduce pests. Worse, large commercial garlic crops are potentially more susceptible to diseases, viruses and a parasite called nematodes which can destroy your garden soil.
Grocery Store Garlic. Softneck Garlic from China.
GARLIC VARIETIES and SUBSPECIES
There are two subspecies of garlic (Hardneck and Softneck) multiple, major groups of varieties, and hundreds of named varieties or cultivars. Allium sativum var. ophioscorodon, called Ophioscorodon, or hardneck garlic, includes porcelain garlic, rocambole garlic, and purple stripe garlic. Allium sativum var. sativum, or soft-necked garlic, includes artichoke garlic, silverskin garlic, and creole garlic. Home gardeners in climates with cold winters (USDA Hardiness Zones 2, 3, 4, and 5) typically grow hardneck garlic. Home gardeners living in warmer climates find that softneck garlic grows well at their location. Even though elephant garlic really looks like garlic, elephant garlic is not actually garlic and belongs to ampeloprasum, the same species as leeks; garlic is from the species sativum. Garlic wrappers and skins vary in color from white, red, purple, and striped purple.
German Porcelain. Hardneck Garlic Harvested in late July.
Selecting a Location for Garlic to Grow. Garlic grows best in a location that receives full sun during the daylight hours. Don't plant garlic in shade. Garlic takes a long time to mature and needs as much sunlight as possible, as photosynthesis is the process by which green plants use sunlight to synthesize foods from carbon dioxide and water.
Soil. Before planting garlic cloves, be sure your soil is ready for your seed garlic. Soil quality has a huge impact on the success of your garlic plants and bulbs. Soil is a complicated and often an overlooked topic. In simple terms, garlic likes loose, fluffy soil full of organic matter and live microbes. The soil should drain well, but still retain moisture. The soil should be alive. A shovel full of good soil holds millions of microscopic life as well as earthworms, nematodes, and bacteria. If your soil is not healthy, garlic failure is usually on the horizon. The importance of pH is essential to understanding how to get nutrients to plants. Garlic grows well in a pH between 6 and 7. If the soil pH is below 5.6, lime is recommended to increase the pH. A high pH reading will prevent some important nutrients from moving into the vascular system of the garlic plant. When looking for reasons why garlic plants look sick, gardeners often suspect insects or diseases. It's true that insects and diseases do cause many plant problems, but often overlooked are poor soil conditions.
Fertilizer. Determine fertilizer needs with a soil test and then follow the recommendations given with the test report. PRO TIP: Don't just add a generic 10-10-10 fertilizer to your soil, if you don't already know what your soil is deficient in. This will likely be a waste of time and money. The true value of a soil test is to help ensure that only needed nutrients are added and in quantities that don't adversely affect your garlic plants. If fertilizer applications are warranted, work the fertilizer into the top 6 inches of soil. Nitrogen (N), phosphorus (P), and potassium (K) are three of the most important elements for plant growth. Sulfur (S) is the fourth most important element. PRO TIP: Don't ignore sulfur requirements when growing garlic. Sulfur comes in many forms. Sulfate-Sulfur is the only form of sulfur the plant can utilize and is often found in aged manure and decomposed compost. If you fertilize with organic material such as manure or compost, make sure the material is well-composted organic matter and not "hot". Fertilize garlic in the early spring by side dressing or broadcasting with a source of nitrogen such as blood meal, bat guano, pelleted chicken manure, feather dust, leather dust, soybean meal, cottonseed meal or another source of nitrogen. Fertilize just before the bulbs begin to swell in response to lengthening daylight (usually in May). Then, plan to fertilize once again, about a month before harvest.
Using a Soil Test as a Guide, Determine What Fertilizer is Needed.
Determine How Much Garlic you Will Need for Planting. Here is a simple calculation you can use to determine how much hardneck garlic you will need to acquire for planting. In this example, we will use porcelain garlic (Music, German Extra Hardy, and Rosewood). A typical porcelain garlic bulb contains between 5 and 7 individual cloves (an average of 6). Each clove is a seed. One pound of porcelain garlic typically contains 5 to 7 garlic bulbs (an average of 6). One pound of porcelain garlic will typically have 6 x 6 = 36 cloves. 36 cloves should yield 36 plants. Garlic is typically planted 6" apart. If you are planting a single, 10-foot row of garlic, let's use these calculations:
10 foot row x 12" = 120 inches ................................................................... Convert feet to inches
120 inches / 6 inches (spacing) = 20 plants. ............................................... Assume 6" spacing of cloves
20 plants / 6 cloves per bulb = 3.3 bulbs .................................................... Assume 6 cloves per bulb
Plan to purchase 3 or 4 bulbs which will likely be about a half pound. Plant the large cloves,
save the smaller cloves for culinary.
Acquiring Seed Garlic. It is now time to buy your seed garlic. After determining which type of garlic you hope to grow, softneck or hardneck garlic (or both), plan to acquire your seed garlic as soon as garlic farms make seed garlic available. Garlic farms typically harvest their garlic in late July or early August, cure it, and make it available in late August or early September. There are many garlic farms, including GROeat Farm in Montana, that have assembled a selection of seed garlic varieties for you to choose from. Seed garlic typically is provided to you as a garlic bulb; Before planting, you seperte the cloves from the bulbs. Some garlic farmers also sell individual cloves. A pound of seed garlic will likely cost $20 to $30 / pound.
Growing Garlic from Bulbils. Garlic is typically propagated and grown from cloves. Garlic can also be grown from bulbils, which are the tiny, clove-like seeds produced in the scape of hardneck garlic. Essentially, the bulbils are clones of the mother plant that can be planted to produce a replica of the plant. The Umbel stores the bulbils and forms at the end of the scape. If you plant bulbils, the first year will produce a "round" that looks like a ping pong ball. Year two will produce a bulb with individual cloves.
Tiny, clove-like seeds produced in the scape of hardneck garlic. Source: www.GroEat.com
Plant Garlic in the Fall. Hardneck garlic is typically planted in the fall, five or six weeks before the first hard frost. In Montana, at our GroEat Farm, we plant hardneck garlic just before Halloween. While the Halloween holiday may bring to mind the ability of garlic to ward off vampires, we get excited about planting garlic. We have planted hardneck as late as December while the soil was not frozen and was still workable. If you missed the fall-planting window, plant in early spring, before April, assuming your soil is workable and the garlic you plant has gone through eight weeks of vernalization or exposure to cold conditions. Bulb growth is typically poor and yields are low if planted in the spring, but not always.
Depending on your location, garlic can be planted from mid-September through early November. PRO TIP: Don't plant garlic too early. Don't plant too early or the garlic will develop green top growth which may die off during the cold winter. Tops grow rapidly the following spring. Large leaves and large plants are required to produce large bulbs. During the fall and early winter, the root system develops even though little top growth occurs.
The Delicate Root Structure on a Hardneck Garlic Clove. 45 Days after Planting. Source: www.GroEat.com
A few days before planting, separate the cloves from the garlic bulb. If the skins come off the cloves, that is perfectly fine. We've planted cloves with and without the skins and they both do equally well. PRO TIP: Soak seed garlic (cloves) for 12-24 hours in 2% soap (not detergent). Another option is to soak cloves in a solution of water and hydrogen peroxide for 10-20 minutes prior to planting. The soak has the potential to kill bulb mite (Aceria tulipae) and eriophyid mite that survives on cultivated Allium species. When soaking garlic prior to planting, likely the outside skins surrounding the cloves will fall off.
Plant the largest cloves with the pointed end up 2-3 inches deep. Cloves should be spaced 6 inches apart, either in a grid pattern or in rows. High-density plantings will typically result in reduced bulb size.
Water. Garlic requires regular watering, during the growing season. But how often should you water garlic? The regularity at which your garlic plants should be watered really depends on a number of details. Your local climate and the amount of precipitation that falls from the sky is one of those details. The type of soil your garlic is growing in is another. During the growing season, garlic needs to be regularly watered, about an inch of water per week with more water during warm, dry, and windy conditions. If there has been consistent rainfall, you likely will not need to water your garlic until the first few inches of the soil dry out. The water needs to reach the plant’s roots, so let the water soak into the soil. You can use a moisture meter to check the moisture of the soil up to a depth of 8 inches. PRO TIP: If garlic sits in very moist conditions such as standing water or flood water, the cloves and developing bulbs can rot and die. Moisten the soil thoroughly every week, then let the soil slowly dry out. Drip irrigation works well. A lack of moisture can reduce bulb size. Stop watering when the leaves start to mature (turn yellow) and stop watering a few weeks before harvest. Excess water as the crop matures delays curing and causes storage problems.
Remove the Garlic Scapes from Hardneck Garlic Plants. Garlic scapes, also known as the floral stems, should be removed as they emerge in May or early June from hardneck varieties. Softneck garlic does not produce a scape. The stem and stalks of softneck are more flexible making them great for braiding. Scapes are removed to deter the plant from sinking energy into the bulbils, which are stored at the end of the scape's Umbil. Instead, let the garlic plant divert the energy into the garlic bulbs and cloves. What happens if you don't remove garlic scapes? Scapes will stunt the growth of hardneck garlic bulbs. Young, small stems can be eaten like asparagus, but they get more fibrous and less edible as they mature.
One of our favorite ways to use garlic scapes is to create a yummy batch of garlic scape dip, with white beans. This easy dip has big flavor and pairs perfectly with fresh veggies and pita chips.
A yummy batch of garlic scape dip, with white beans.
Remove Weeds. Garlic plants do not do well if they have to compete for water and nutrients. Garlic cannot stand much competition. Weeds steal precious nutrients and water from your garlic plants. For garlic producers, a weed is any plant other than garlic. Control weeds by regular shallow cultivation, but avoid damaging the delicate root structure of the garlic. Mulching with straw, compost, grass clippings or leaves will smother weeds. PRO TIP: Don't mulch with hay, as hay contains lots of seeds.
Mulches. Organic mulches, such as straw, leaves and grass clippings help conserve water and can help reduce weeds. PRO TIP: Keep in mind that when mulch decomposes, the nitrogen-producing bacteria in your soil may divert their attention to breaking down the mulch. Straw, wood chips, and grass clippings can deplete nitrogen in the soil as it breaks down, so an additional fertilizer is essential if using these materials as mulch.
Harvesting Hardneck Garlic in Late July. Source: www.GroEat.com
Garlic is ready for harvesting when the lower three leaves start to brown and wilt to the ground. Harvesting typically occurs during the mid-summer months. At our GroEat Farm in Montana, we typically harvest late July. The only way to be sure if the garlic is ready for harvest is to dig up a bulb or two to check the progress. Harvesting too early will likely result in smaller bulbs and smaller cloves that don’t store well. Harvesting too late (a common mistake) and leaving the bulbs in the ground too long can cause the cloves to burst out of their skins, making them vulnerable to disease and shorter storage time.
Don't yank or pull the garlic out of the ground. Instead, gently dig around the plant using a garden fork. Loosen the soil gently and keep the tines of the fork away from the bulbs so you do not damage or nick the bulbs. Fragile, Handle with Care. Don't drop, throw or rough-handle the garlic. Garlic that has been damaged likely will not store for very long.
Each planted clove will likely produce one plant with an attached bulb. Each bulb should yield 5+ cloves at harvest. Softneck garlic typically produces a smaller bulb with more cloves, as compared to hardneck garlic.
Curing garlic involves a drying process away from direct sunlight. Curing can be achieved by placing the entire garlic plant (bulb, roots, and green plant material) on a mesh platform that allows air to circulate, or hung in bunches, from ropes. Initially, the entire plant will be rather heavy, though after a few weeks of curing the weight will be less. The plants are to be hung with adequate air circulation or on open racks off the floor. Curing takes two to three weeks. Cure garlic indoors, such as in a shed, shop, garage or location that has constant air circulation. Incorporating fans works well too. Don't cure garlic in bright sunshine, as the sun's rays can cause sunburn on the exposed bulbs. At our farm. we sort garlic by variety and size. We hang bunches of garlic to cure on straps that are hung between two walls in our shop. Surprisingly, garlic gives off very little odor as it cures. It’s only when the cloves are crushed and the allicin and other compounds combine to create that authentic garlic smell. Typically, the curing process is finished when there’s no apparent moisture, when you cut into the stems, just above the bulbs. The leaves and root structure should be dry and almost crumble to the touch.
Trim Garlic Stem, Leaves, and Roots from Bulb. Once the garlic is cured, cut and remove the plant's stem and leaves from the bulb, leaving an inch or two of the stem attached to the bulb. Brush any remaining soil from the roots and trim the roots with scissors or pruners. Remove any bulb wrappers that appear to be loose or begin to flake off, but don't remove too many of the wrappers. The paper wrappers help protect the cloves inside.
Hardneck Garlic Curing in Bunches, Held Together using Reusaalbe Zip Ties. Source: www.GroEat.com
Selecting Seeds for Fall Planting.
After harvest, look for those really large garlic bulbs. If you see a few that are particularly large, keep these large bulbs as planting stock for fall planting. Contact a garlic farm to learn more about other garlic varieties you could try to grow. Over time, you will likely determine which cultivars grow best at your location.
Handle garlic gently so it does not bruise. Garlic can be stored as whole heads of garlic in a cool, dry, dark place. Do not store garlic in plastic bags as mold will likely develop. Whole heads of hardneck garlic, stored in a cool, dry, dark place can last until March or so, which is likely when the cloves will begin to develop green shoots and a root structure. Peeled cloves can be stored for long periods of time (2+ years) in a chest freezer at -6 degrees Fahrenheit (°F). Frozen cloves will soften slightly over time. Do not store garlic in the refrigerator because cool temperatures combined with moisture stimulate sprouting and mold growth. Properly stored garlic should last until the next spring when the garlic may begin to sprout.
PRO TIP: Do not store garlic in oil at room temperature. Garlic in oil mixtures stored at room temperature provides the perfect environment for Clostridium botulinum to grow and produce a toxin that can kill you or your family. Garlic has low acidity, and there is no free oxygen in the oil, at warm temperatures. The same hazard exists for roasted garlic stored in oil.
If you have additional questions, please contact me. Jere Folgert. GroEat Farm. jfolgert (at) Gmail . com
Published April 16, 2016
GroEat Farm, Montana