Growing Garlic in the Home Garden

Garlic has been cultivated since ancient times. Today, it is used as a condiment and flavoring in gravies, tomato sauces, soups, stews, pickles, salads, salad dressings, and breads.

garlic in a bundle
Garlic can be a great addition to the Iowa vegetable garden.  (1)

Garlic (Allium sativum) is a member of the Amaryllidaceae family. Other edible members of this family include onions, chives, leeks, and shallots.

While garlic and onions are similar, there are differences. Garlic has flat leaves rather than the round, hollow leaves of the onion. Garlic produces several small bulbs called cloves rather than one large bulb. Each garlic bulb contains several cloves enclosed in a white or purplish parchment-like sheath or skin.


Types of Garlic  |  Growing Conditions  |  Planting  |  Care  |  Harvest & Storage  |  Scapes  |  Potential Problems  |  FAQs  |  More Information


Types of Garlic

Hardneck

Hardneck cultivars (Allium sativum var. ophioscorodon) produce cloves that surround the base of a hard flower stalk. They grow well in Iowa but do not store as well as softneck cultivars. 

This type of garlic is also known as "top-setting" garlic because, in addition to producing a bulb of cloves underground, it forms bulbils or bulblets at the terminal end of a hollow seed stalk. The bulbils are initially enclosed in a globe-shaped structure. The outer sheath eventually splits, exposing the cluster of small, pea-size bulblets.  

Hardneck cultivars are divided into three common types: Rocambole (6-11 cloves; twisted scapes), Purple Stripe (8-12 cloves), and Porcelain (4 large symmetric cloves). 

Suitable cultivars for Iowa gardens include ‘Asian Tempest,’ ‘German Red,’ ‘Merrifield Rocambole,’ ‘Music,’ and ‘Spanish Roja Rocambole.’ 

softneck garlic
Softneck garlic is what is typically found in grocery stores  (3)
hardneck garlic
Hardneck garlic has a flower stalk in the center of the bulb. (2)

Softneck

Softneck cultivars (Allium sativum var. sativum) look more like the garlic bulbs we see in grocery stores. While many perform better in warmer climates, some softneck cultivars are suitable for Iowa’s colder temperatures. They usually do not grow a flower stalk. Softneck cultivars are generally more productive and easier to store than hardneck cultivars. 

Softneck cultivars suitable for Iowa gardens include ‘Inchellium Red,’ ‘New York White,’ and ‘Susanville.’

Elephant

Elephant or greatheaded garlic (Allium ampeloprasum) is not a true garlic. It is actually more closely related to the leek. Elephant garlic does produce segmented bulbs similar to garlic. However, elephant garlic has a much milder garlic flavor and may be 3 to 4 times the size of true garlic.

garlic growing in garden
Garlic grows best in full sun and fertile, well-drained soils. (4)

Growing Conditions

Garlic grows best in well-drained, fertile soils high in organic matter. Garlic grown in heavy, clay soils often produces misshapen bulbs. Heavy clay soils can be improved by incorporating organic matter, such as compost or well-rotted manure. Garlic also requires full sun.

Planting

Garlic does not grow well or reliably from seed. Plant cloves obtained from garden centers or mail-order companies in the fall (October to early November). Alternatively, garlic cloves can be planted as soon as the ground can be worked in the spring (late March to early April in central Iowa).  The highest yields are obtained from the largest cloves planted in the fall. Do not plant garlic cloves purchased from grocery stores, as these are usually softneck cultivars from warmer regions that are not well adapted to Iowa’s climate.  

planting garlic cloves
Garlic is planted in fall for harvest the following summer.  (5)

Plant large cloves 1 to 1.5 inches deep with the pointed side up, 3 to 5 inches apart within rows spaced 18 to 24 inches apart. Start with large cloves, as they produce larger bulbs. 

Fall-planted garlic should be mulched in November with a 4- to 6-inch layer of weed-seed-free straw to help prevent winter injury. In early spring, move the straw between the rows to allow the garlic foliage to emerge. 

Top-setting garlic varieties can also be grown from the bulbils or bulblets at the top of the seed stalk. The bulblets should be planted in early spring where they can remain for 1 1/2 years. The bulblets will form larger, unsegmented bulbs called "rounds" by the end of the growing season. Left undisturbed in the ground, they will form a cluster of cloves by the end of the following summer.

Care

straw on emerging garlic
As garlic emerges in spring, pull back the straw and use it between the rows for weed suppression.  (6)

Garlic requires more fertilizer than many vegetables. Apply and incorporate 1 to 2 pounds of an all-purpose garden fertilizer, such as 10-10-10, per 100 square feet of garden area prior to planting. Lightly incorporate one additional pound per 100-foot row of the all-purpose garden fertilizer in a band 4 inches to the side of the developing plants 3 to 4 weeks after plants emerge in the spring.

Garlic requires 1 inch of water each week. Irrigate garlic once a week during dry weather. Stop irrigating in late July to allow the foliage to die down prior to harvest. This also helps reduce disease spread and staining of the paper covering on the bulb.

Garlic has a shallow root system. Control weeds with shallow cultivation or by applying mulch, such as straw or grass clippings, between rows. Mulch will also help to conserve soil moisture.

Harvest and Storage

drying garlic
After harvest, lay garlic in a well ventilated space to dry.  (7)

Harvest garlic when the foliage begins to dry. In Iowa, garlic is usually harvested in July or August. Carefully dig the bulbs with a garden fork or shovel. 

Dry garlic in a warm, dry, well-ventilated location. Place the garlic on an elevated wire screen or slotted tray to promote drying. 

When the tops have dried, cut off the dry foliage 1 inch above the bulbs. Also, trim off the roots and brush off any loose soil. Place the bulbs in a mesh bag or open crate and store them in a cool (32 to 40°F), dry (65-70% relative humidity) area. Garlic can be stored for three to six months if properly dried and stored. 

An alternate way to store garlic is to braid the foliage together immediately after harvest, dry and then hang the braided garlic in a cool, dry location.

Garlic Scapes

garlic scapes
Garlic scapes can be harvested to use in cooking.  (8)

Hardneck garlic cultivars will produce a scape or flower stalk from the center of the leaves in mid-to-late May. Removing the scape is advised, as it will help the bulb grow larger because the plant will put energy into bulb production rather than flower and bulbils/bulblets production.

Harvest garlic scapes when they are immature, are fully extended above the leaves, and have begun to curl but before the stalk straightens and the bulbous end opens to reveal flower buds. Cut the stalk off as low as possible without cutting off any leaves.

Young scapes can be used in cooking to provide mild garlic flavor when chopped and added to eggs, salads, stir-fries, pickles, or to make pesto. They are also attractive additions to floral arrangements.

Potential Problems

Yellow Leaf Tips

Many garlic cultivars are susceptible to yellow tips. The development of yellow tips early in the season (before bulbing) may drastically reduce yields. It is usually a sign of water stress, nutrient deficiency, or disease.

Unsegmented Bulbs

An occasional problem gardeners encounter is the production of unsegmented bulbs or "rounds." This may be the result of planting cloves that are too small, planting in late spring, or poor growing conditions during the growing season.

Poor Emergence

Most garlic diseases are either soil- or set-borne and usually can be controlled with proper rotation and planting disease-free sets. Before planting, check each clove for signs of disease. Discard any infected or bruised cloves because they will decay in the soil. 

If garlic cloves from the grocery store were planted, emergence would likely be poor. Most garlic in stores is treated to prevent sprouting.  While this is good for storage, it is bad for growing, and often, the treated garlic will rot before it sprouts.

Early Emergence

While not a regular occurrence, it is not unusual for the foliage of fall-planted garlic to emerge early during a mid-winter warm-up in January or February. While in Iowa garlic normally begins to emerge from the ground in mid-March to early April, mild winter weather can encourage premature growth. 

While the premature emergence of garlic foliage is undesirable, the danger is not as great as it may seem.  The foliage of garlic can tolerate cold temperatures (down into the 20s °F).  Often, typical winter weather (cold temperatures and snow) returns, delaying further growth.  A blanket of snow is especially helpful.  The snow discourages additional growth and also protects the foliage from extreme cold.

Once normal winter temperatures return it will be beneficial to add an extra layer of mulch, especially if there is poor snow cover, in case the temperature gets down into the teens or lower.  At temperatures below 20°F, the foliage will likely see some damage.  However, even if the foliage is damaged or completely killed to the ground, the garlic usually regrows – although the resulting crop will likely be smaller as energy was lost producing leaves that were then destroyed. You can remove the mulch once temperatures are consistently warmer and spring growth is appropriate and expected. 


garlic
Hardneck cultivars of garlic are well-suited for Iowa gardens.  (9)

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Photo credits: 1: Cindy Haynes; 2: Helga1/AdobeStock; 3: Alexander/AdobeStock; 4: Cherkasova Alie/AdobeStock; 5: beerfan/AdobeStock; 6: Vlad Varšavskij/AdobeStock; 7: grovik/AdobeStock; 8: sever180/AdobeStock; 9: physyk/AdobeStock

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Last reviewed:
July 2024