Horticulture/Garlic

'Allium sativum L., commonly known as garlic, is a species in the onion family alliaceae. Its close relatives include the onion, shallot, leek, and chive. Garlic has been used throughout recorded history for both culinary and medicinal purposes. It has a characteristic pungent, spicy flavor that mellows and sweetens considerably with cooking.

Description
A bulb of garlic, the most commonly used part of the plant, is divided into numerous fleshy sections called cloves. The cloves are used as seed, for consumption (raw or cooked), and for medicinal purposes. The leaves, stems (scape), and flowers (bulbils) on the head (spathe) are also edible and are most often consumed while immature and still tender. The papery, protective layers of "skin" over various parts of the plant and the roots attached to the bulb are the only parts not considered palatable.

Growing Conditions
It is preferable to sow Garlic cloves in late autumn, but they can also be sown in early spring, although you should expect a smaller yield from spring planting.
 * Spring planting:While not advisable you can plant Garlic in late winter or early spring, no later than March, but you will need to chill the garlic prior to planting in order to break it out of its dormancy. You can expect smaller yields from spring plantings, but it also reduces the risk of the plant being damaged by the winter cold.
 * Autumn planting:This is the more common time to sow Garlic and you can expect it to produce superior yields. There is a European tradition of planting on the shortest day of the year but this is not necessary, the best time to plant is after the first major frost of the year, usually between mid-October and late November depending on local climate.  Garlic is winter hardy but please be aware that the plant can be damaged if the temperature gets very cold and there is minimal snow cover, in this case cover the Garlic with straw to insulate it.

Garlic prefers a site that receives plenty of sun and where the soil is not too damp, Garlic cannot grow in shade. Plant cloves individually, upright (with the flat end pointing down) and about an inch (25 mm) under the surface. Plant the cloves about 4 inches (100 mm) apart. Rows should be about 18 inches (450 mm) apart.

Garlic is not particularly demanding, it will grow in acidic, neutral and alkaline soils, however, it prefers light free draining soil and will not grow well in clay soil or soil that is consistently damp. Garlic does not need very rich soil but prefers soil that is well cultivated with plenty of organic matter, compost or manure.

Garlic planted in the Autumn should produce shoots above ground in early spring, if not there is still time to plant a spring crop which will produce shoots soon after. Garlic does not require much in the way of maintenance but should be watered sparingly in extended dry periods and covered if you experience an extended period of heavy rain. You can apply fertiliser in late March and mid May to encourage growth but this is not necessary to obtain a decent crop.

Uses
Garlic is widely used around the world for its pungent flavour, as a seasoning or condiment or to enhance other flavours. Depending on the form of cooking and the desired result, the flavor is either mellow or intense. It is often paired with onion, tomato, and/or ginger. It is very widely used in Lebanese cuisine: many Lebanese salads contain a garlic sauce. The parchment-like skin is relatively inedible, much like the skin of an onion. The skin is typically removed before cooking, though sometimes alternative approaches are used, such as slice garlic head crosswise, coat in olive oil, roast until the garlic is well cooked, and then the roasted garlic separates quite easily from the skins (by pulling it out, shaking it out, and/or squeezing it out). The term 'clove' is sometimes misinterpreted to mean the whole garlic bulb (head).

Garlic is commonly stored in cooking oil with herbs to yield an oil infused with flavour. Garlic-infused oils are widely available. Care must be taken preparing such, as there is a risk of botulism developing in the oxygen-free oil if the product is not stored properly. To reduce the risk of botulism, the oil containing the garlic must be refrigerated and used within one week. (see Caution below). Commercial producers use a combination of salts and/or acids to eliminate the risk of botulism in their products.[8] In Chinese cuisine, the young bulbs are pickled for 3–6 weeks in a mixture of sugar, salt and spices. Pickled garlic is available at supermarkets. The shoots are often pickled in Russia and states of the Caucasus and eaten as an appetizer.

Immature scapes are tender and edible. They are also known as 'garlic spears', 'stems', or 'tops'. Scapes generally have a milder taste than cloves. They are often used in stir frying or prepared like asparagus. Garlic leaves are a popular vegetable in many parts of Asia, particularly in particular Chinese, Vietnamese, and Cambodian. The leaves are cut, cleaned and then stir-fried with eggs, meat or vegetables.

Maintenance
harvested cloves must retain their outer covering to avoid dehydration,cloves harvested during late summer affect the drying and storage when wet is required this achieved by storing at 0-4 degrees centigrade,although this cold storage my induce dormancy treatment with growth inhibitor promote storability. all cloves selected for planting should be disease free, good quality and well matured.

Propagation
Garlic is grown from Individual cloves. Each clove will produce one plant with a single bulb, which may in turn produce up to twenty cloves. the cloves will not germinate naturally just like any other seeds this because garlic cloves posses some physiological dormancy which has to be treated for their sprouting. cold treatment 0-4 degree inside refrigeration at a period of between 2–3 weeks will break dormancy and induce sprouting another method of breaking that dormancy is by use of hormone gibbellin GA3 commercially obtain with trade name rootex, concentration of 20% has been found to induce rooting, the basal plate of the cloves is treated and cloves planted in media in upright manner. experimental research as shown a faster and vigorous growth rate once treatments are administered. in temperate and sub tropics chilling can be achieved naturally by planting cloves before winter begin this natural mechanism will help treat the cloves and at the beginning of summer 100% sprouting will be obtained

Harvest
The trickiest part of growing Garlic is determining when to harvest your crop, harvest too early and your cloves will be small, harvest too late and the bulb will have started to split, Traditionally in Europe Garlic would be harvested on the longest day of the year but this is not always the best time to harvest. As garlic matures the leaves turn brown and begin to die, this is your cue to harvest your garlic, this can happen any time between June and August so you will need to keep an eye on your crop as it matures and you should harvest when the leaves are about 50% green and 50% brown. It can also be beneficial to pull a single garlic when the leaves turn to assess if the bulb is mature enough, if they are still small you can probably afford to leave them a bit longer, it they are starting to split then you know that you will have to harvest your crop immediately.

The temptation when harvesting is to pull your garlic from the ground by the stem, it is better, however, to gently lift the garlic from underneath with a garden fork. Once picked it is essential that the Garlic is dried properly or it will rot, it is also important at this stage to NOT wash the garlic as this may also cause rot. Fresh Garlic can also be consumed but without curing can only be stored for a short period of time. Once you have harvested your garlic make sure that you do not remove the stem and leaves as the Garlic will continue to draw nutrient from the plant, also do not leave the garlic out in the sun for any length of time as it can scorch the garlic and leech the flavour from it. The Garlic should be stored in a dry place at room temperature that is not in direct sunlight, they will need good air movement to prevent spoilage so they can benefit from being hung by their stems. The curing process takes about a month, anywhere between 14 and 25 days.

Garlic will keep for a number of months after curing but will need to be stored in suitable conditions, usually at room temperature and in an environment with enough humidity to prevent the garlic from drying out. Once cured you can either remove the leaves and stems or if you prefer remove the leaves and use the stems to braid your garlic together.

Pests & Diseases

 * Pests: On the whole Garlic is resilient to most pests, it is often used in companion planting for this reason, however, it is affected by some pests.
 * Bulb Mites: Bulb mites can grow up to 1mm long. They are slightly off-white and shiny, with a bulbous shape. Usually found clustered in the roots of the plant bulb mites can stunt plant growth, resulting in smaller crops. Bulb mite can also cause garlic to rot during storage and as they survive from one season to the next it is advisable to use crop rotation and rotate to a non-allium crop.
 * Pea Leafminer (Liriomyza huidobrensis): Adult Leafminers are small black and yellow flies that lay eggs within the leaf tissue of plants. The small white larvae hatch and tunnel inside the leaves, causing a pattern of damage that is visible to the eye.  Damage to garlic is negligible and mainly cosmetic as leafminers only attack the leaves, however, leafminers can pose a threat to other vegetables where the leaves are the main crop.
 * Wheat Curl Mite (Eriophyes tulipae): The Wheat Curl Mite is small and difficult to see, but possible infestations can be treated by immersing the garlic clove in hot water, but be careful as water that is too hot may kill the garlic. Wheat curl mites do not present a major threat to growing garlic unless the infestation is severe.  Sever infestations present themselves by stunting growth and causing the leaves to become streaked and twisted.  The main threat is to harvested garlic as the mite can cause the bulbs to dry out and crumle, plannting affected garlic increases the risk of Yellow Streak Virus.


 * Diseases:
 * Garlic Rot: This is probably the most common garlic disease. There are two frequently encountered rots:
 * Basal Rot (Fusarium oxysporum): Basal rot is a slow developing condition. Affected garlic plants show gradual yellowing and leaf dieback. There is sometimes a white fungal growth visible at the base of an infected bulb leading to the bulb rotting. Symptoms continue to get worse even after harvesting. Basal rot is favoured by higher temperatures and hence more common in warmer climates.
 * White Rot (Sclerotium cepivorum): The symptoms of white rot are very similar to those of basal rot, however it attacks the growing garlic more quickly and is more likely to kill the plant outright. White rot prefers cooler temperatures. Dipping seed garlic in hot water before planting can reduce the chance of white rot but be careful: too high a temperature could kill the garlic itself.
 * Rust (Puccinia porri):Rust first shows as leaf blotches of a reddish orange colour. If a plant is heavily infected then the leaves turn yellow and can collapse completely. Garlic plants infected by rust will produce a lower than usual yield and can produce deformed bulbs. Heavily infected plants can die.
 * Downy Mildew (Peronospora destructor): Downy mildew can be recognised by an off-white, sometimes slightly purple, furry growth on the leaves of the garlic plant. The leaves go on to yellow then collapse. Since downy mildew is airborne, patterns of yellowing often follow prevailing wind directions in a large crop. Downy mildew can kill young plants and causes stunting in older ones.

Companion Planting
Companion planting is the practice of growing plants together that provide mutual benefits to each other. Garlic is a particularly useful plant in companion planting as it can assist other crops in a variety of ways.

Garlic Deters many pests including:
 * Aphids
 * Carrot root fly
 * Japanese Beetles
 * Root maggots
 * codling moths

It is also supposed to deter snails and even deer, but due to the stubbornness of these pests I would not expect any major success, additionally concentrated garlic sprays can be used to deter white-flies, aphids and fungus gnats among others.

Garlic is also a natural fungicide as well as pesticide, it accumulates sulpher, which is a naturally occurring fungicide and the powerful antibiotic and anti fungal compound allicin is released when garlic cloves are crushed. This also occurs when the clove is bitten into. Thus pests attacking garlic are likely to release its natural pesticide.

Companion planting Garlic is beneficial to most vegetables and soft fruit, as well as roses as it deter Aphids and helps prevent blackspot. Garlic is particularly beneficial to Carrots, lettuce and cabbage as it deters many common pest and can also improve the flavor of some vegetables; including Beetroot and cabbage.

Garlic should not be planted with Legumes, peas or potatoes as it can negatively affect their growth and flavor.