The Adaptive Seeds Guide to Growing Garlic

‘All Things Garlic’ – Our Guide to Growing Organic Garlic

At Adaptive Seeds garlic is one of our favorite crops! During garlic seed buying season we receive a lot of inquiries on how best to select, grow and store garlic, so we’ve decided to share our best tips and tricks for growing organic garlic. We cover some basic (and not so basic) info about how to grow garlic organically and care for this kitchen staple.

Getting Started
First, it is good to know what different kinds of garlic are available. We offer a selection of the two main types of garlic at Adaptive Seeds– Hardneck and Softneck.

Varieties include: Creole: Donostia Red, Rosso di Sulmona; Porcelain: Hadrut, Music; Purple Stripe: Shvelisi (Chesnok Red), Zeramarez; Glazed Purple Stripe: Vekan; Marbled Purple Stripe: Jupiter, Khabar; Unclassified: Yuggoth.

Varieties include: Silverskin: Persephone White and St. Helens; Artichoke: Polish White.

Soil Preparation and Fertility
Garlic is a green, leafy plant for most of its life cycle. This means that it requires plenty of nitrogen for healthy, vigorous growth. But it is also a bulb, like a tulip, and so needs a fair amount of phosphorous as well. We fertilize our garlic prior to planting with a 4-4-4 chicken manure product.  In the Pacific Northwest many soils are low in calcium and sulfur. In this situation gypsum is a great amendment. 

Because garlic is in the ground for so long, it requires an additional application of fertilizer in the spring. We top dress in early April with fish bone meal (4-16-0) because our soils are very deficient in phosphorous.  If your soil has adequate phosphorous, top dressing with a good source of nitrogen (such as blood meal or feather meal) is recommended. We also apply a foliar mix of fish emulsion and kelp extract 2 – 3 times from late April to early May.

 Garlic “Seed” Preparation / Cracking and Planting
In preparation for planting, the bulbs need to be cracked; that is, the outer papery hull needs to be removed from the bulb and the cloves need to be separated and sorted for easy planting. 

It is important to use only firm garlic bulbs and cloves for seed!

If cloves give a little, that is okay, but NEVER use a clove that is soft or has obvious mold damage. The vigor of the plant and the size of the garlic bulb at harvest are determined by both the size of the parent bulb and the size of the parent clove. For this reason, it is best to choose medium-large size bulbs and cloves when planting. We use only the 75% largest cloves for planting and there is no need to peel the clove wrappers. The larger the clove, the more energy resources the young plant will have to draw upon in its initial stage of growth. Smaller cloves can be eaten or planted closer together for green garlic – think green onions, but garlic!

For us in the Willamette Valley, the best time to plant garlic is October, but it can also be planted through February. Later plantings will result in smaller bulbs. Plant one clove every 6-8” in rows that are 1′ apart. Make sure the clove is covered by at least 1-2” of soil, with the blunt end pointing down. 

Care and Cultivation
Garlic should sprout and come up within 2-4 weeks, but this can vary depending on seed storage, and climate and soil conditions.  Many growers mulch garlic 2-3” thick with straw or leaves. This helps keep weeds down and limits fluctuations in soil temperature and moisture content. Mulching can be done at planting time because the first leaf shoot that the bulb sends up is a specialized leaf that can break through barriers such as soil and mulch.

In our area, garlic tends to grow 4-6” in the fall, then go dormant from December – February. Growth begins again late February to early March (this is when spring fertilizing begins). Garlic is very sensitive to weed pressure and needs to be cultivated regularly to be free of weeds.

Pay attention to the leaf color and shape during the growing season, and cull plants that look off – yellow or curled leaves, deformed stems, stunted growth, etc.

By late May, the plants stop leaf production and begin to bulb out. Stop fertilizing at this time.  May is also a good time to scout for “doubles” – when two plants emerge from one spot. Pull out any doubles until only one plant remains. Leaving doubles in the ground results in smaller bulbs. We joyfully eat our doubles as green garlic!

In mid-May to June, the hardneck garlic (and potentially some of the softneck) will send up a flower stalk from the center of the plant, this is called a garlic scape. Wait to remove the scape until it curls (or whips) around itself, then pinch it off at the base. Also known as garlic whistles (for the sound they make when pulled out), they are a gourmet delicacy: a mild garlic flavor with the texture of asparagus. YUM! We highly recommend garlic scape pesto! (And pickles!) Removing the scape allows the plant to send more energy to its bulb, and results in bigger garlic, so even if you don’t want to eat it, it is important to break it off. If you leave the scape on it will flower and produce little bulbils that can be planted. These will form garlic bulbs in two years.

Fortunately, the rainy season takes care of most of the watering needs of garlic plants here in the Pacific Northwest. In late April to mid-May, if the rain stops, the garlic still needs to get regular watering. Irrigate garlic at least once a week until two or three weeks before harvest. In mid-late June, plant leaves will begin to yellow from the tips downward and the outside leaves inward.  Stop water when a few of the leaves have dried down, typically the middle of June.

Harvest
Plants are ready to harvest when 50% of the leaves are all dried down. If you wait until the entire plant is dry, you will lose a lot of the wrappers during harvest and/or may end up with bulbs that have cracked open – both result in decreased storability.

For us, harvest of mature bulbs begins with Artichoke types in late June or early July, hardnecks around mid-July, and finishing off with Silverskins by the end of July. Harvest time can be a few weeks earlier or later depending on weather and growing conditions each season.

To harvest, simply loosen the soil and pull the garlic out of the ground. But be careful, fresh garlic bruises very easily and will not store well if the neck or cloves are damaged, so it’s best not to drop or throw bulbs. If a bulb is damaged in harvest, it is best eaten fresh. Uncured, fresh garlic is a real treat! 

Even with our tractor digging tool bar which makes garlic harvest a lot easier, we sometimes need to use a digging fork to loosen the soil around the base of the bulb. Again, take care not to stab the bulb with the fork. (We call this farmer blight.) Freshly harvested garlic should be kept out of direct sunlight so don’t let it linger too long out in the field or garden when harvesting.

Storage/Curing
Garlic needs to be cured for it to store properly. If it is not cured, it will not keep for very long and will likely develop mold. The storage and curing location for garlic should be out of direct sunlight and have good air circulation. We use our barn with some garlic lying on pallet racks and some hanging from the rafters. 

It is not recommended to cut leaf stalks (necks) before curing: Garlic will cure better and last longer if it is cured with them on. Be sure to remove as much dirt as possible from the roots (we do this in the field during harvest).

The simplest way to store and cure is to tie a string around the stalks of a dozen or so plants and hang the bundles in a shed or garage.

Post Curing
To prep garlic for long term storage, clip the leaf stalk, trim the roots, and remove as few of the papery leaf sheaths as possible – just enough to be ‘clean.’ Note that the more wrappers on the bulb, the better and longer it will store. Softneck varieties are perfect for braiding. Hardneck varieties should be eaten first as they won’t store as long. We bring all of our garlic into the house from the barn when the weather gets cool and moist to avoid sprouting. At room temperature, our Silverskin garlic stores through spring.

A Note About Disease
Garlic is susceptible to fungal, bacterial, and viral diseases that may be naturally occurring in soils and/or introduced by critters in much of the US. Practicing wide crop rotations (5+ years between any onions, garlic, or leek crops) and diligently removing any plants that look like they may be infected are two effective tools for limiting disease in garlic. Infected or questionable garlic should not be planted. If garlic rust is a problem try planting late maturing silverskin types. In western Oregon they seem to be less susceptible to rust.

Additional Resources
Much of this information is adapted from:

Growing Great Garlic by Ron L. Engeland, Chelsea Green Publishing, 1991.

The Complete Book of Garlic: A Guide for Gardeners, Growers, and Serious Cooks by Ted Jordan Meredith, Timber Press 2008.