Time to get ready to plant garlic & shallots

Posted: September 27, 2011

The summer growing season is rapidly winding down, so it’s time to begin planning for the 2012 garlic & shallot crop. The best time to plant garlic and shallots is mid-October throughout much of the Mid-Atlantic region.

This gets the cloves in the ground early enough to get a good root system developed while late enough to minimize shoot emergence.  The roots need to be far enough along to hold the clove in place in order to prevent frost heaving. Both crops must get sufficient winter chilling (vernalization) for the individual clove you plant to form a new segmented bulb in the spring. It is probably no surprise that meeting the chilling requirement for garlic in PA is seldom a problem. Fall planted shallots will grow bigger and yield more individual shallots than those planted in the spring.

One of the truly great things about garlic growing other than the opportunity to eat it fresh in a multitude of flavors is the general disdain for the crop by most garden pests. Rabbits, deer, skunks, and most other garden marauders generally leave garlic alone.  With this in mind, there are a few considerations for growing great garlic:

-Rotate your crop on at least a three year cycle (five is better) to prevent most rot diseases. Garlic is an Allium, so must be counted along with shallots, onions and leeks. Disclaimer: My home garlic gets rotated with tomatoes and peppers every other year, thus making this a 2 year rotation. I’ve taken to including beneficial microorganisms into the soil to compete with disease-causing bacteria and fungi. Gardens Alive markets a product called Root Guardian and some garden centers and websites sell RootShield. These are specific fungi that have demonstrated impressive levels of disease control and fit under organic gardening standards.

-Garlic competes poorly with grasses and other aggressive weeds, so maintain a weed free patch. Mulching with clean straw after planting goes a long way to keeping weeds under control.

-Plan on an irrigation system as the bulbs require 1-2” of water per week from  early-April to maturity. Garden center soaker hose makes for simple yet water conserving irrigation throughout the garden. If you want to move to the next level, it is easy to build a scaled down commercial-type irrigation system. For more information on these systems request: HortReport Garden Enthusiast Series #1, Building and Operating a Fruit and Vegetable Irrigation System from the Penn State Franklin County Cooperative Extension office.

-Garlic is a heavy nitrogen (N) user. Rates of #4 / actual N per 1,000 ft2 is recommended. This fertilizer should be supplied in split applications. Apply #1 N at planting and the remainder in two springtime applications in late April and again in late May. 10-10-10 fertilizer contains just 10% actual N, therefore, #10 is needed to get #1 of actual nitrogen.

- Garlic responds well to high levels of organic matter. You will get bigger, better formed bulbs in soils that have higher levels. Well-made compost and green manure crops are both excellent methods to increase soil organic matter.

-Mulch the newly planted cloves with 2-3” of loose, clean straw for weed control, moisture, and soil temperature modification. Sometimes straw mulch can create a weed problem if too much seed is left in the straw from harvest. Do not let the wheat, oats, barley or rye, get well-established as they will compete with the garlic thus making smaller bulbs. Dropping bales of straw repeatedly on a hard surface before you apply the mulch to the soil can shake much of the seed loose before taking the straw to your garden.

-Plant the largest and cleanest cloves you can find. Bigger cloves mean bigger bulbs at harvest. Cloves that appear free of disease are most likely to produce a good crop. Garlic comes in many colors and flavors from white to red and purple and mild to very pungent. Elephant garlic is actually classified as a leek and is very mild compared to the flavor of a true garlic, but is still fall-planted.

-There are 2 primary groupings of garlic; soft and hardneck. Soft types are used in creating braids and garlic ropes while the hardnecks are sold only as bulbs. This authors experience as well as many others indicates that unless your soil is very well-drained, stick to hardneck types as the softnecks are more prone to soil-borne diseases in our generally heavy soils. Also, avoid using supermarket purchased garlic bulbs for your planting stock. Most of this garlic is adapted to California or even China and will probably do poorly in the Mid-Atlantic.

-Cut off the flower heads/ scapes once they emerge fully in June. Do not let them mature as they will drastically reduce the size of your bulbs. Some people will stir fry them to add some relatively mild garlic flavor to a dish. Shallots will also benefit from flower top removal. If this is a rainy period, apply a copper-based fungicide / bactericide immediately after scape removal to reduce stem rots.

-Harvest the new crop after 40-60% of the leaves have yellowed. Dig a couple of bulbs before you start the major harvest and be sure the bulb looks ready for harvest. The outer skin should be dry and the bulb well segmented. If the cloves have begun to pull away from the stem, you have waited too long. Not all varieties of garlic get harvested at the same time as there are early, mid and late season types.

-Most garlic in the Mid-Atlantic is harvested by mid-July. After under digging the plants, lift them from the soil, shake off the excess soil and move the garlic to a dry location for curing. Curing will go better if the plants are spread on some kind of mesh with good ventilation and minimal contact between the bulbs. Curing typically takes 2-3 weeks. Once the outer 2 skins are dry, the process is complete and the bulbs are ready to be cleaned up prior to storage.

-To prepare the bulbs for storage, cut the stem off at the top of the bulb just above the tops of the cloves. Remove the remaining soil from the roots and cut the roots off close to the base of the bulb. Garlic is best stored in a cool area at higher humidity such as a root cellar. Some varieties store better than others.

-Shallots are grown pretty much the same as garlic including planting date and harvest timing.

There are over 100 varieties of garlic available from seed suppliers. If you are seeking a large bulb with moderate flavor and keeping characteristics, try starting with the variety Music. For a nearly complete list of garlic suppliers contact the Garlic Seed Foundation at Garlic planting stock is also available from an ever-growing list of seed companies. Among these suppliers are Burpee Seeds, Johnny’s Selected Seeds, and Territorial Seeds.

Steve Bogash is the Penn State Cooperative Extension Educator for Horticulture/Small Fruit. Penn state is committed to affirmative action, equal opportunity, and a diverse workforce.