Garlic is mysterious.
Associated with herbalists, witches, gourmet cooks, and with repelling vampires and werewolves, it has a long and fascinating history.
It is mysterious because most cultivars set no true seed, making hybridisation to create new varieties virtually impossible. It matures easily, further complicating genetic studies. Although it is a member of the onion family, garlic creates a number of small bulbs (called cloves), rather than growth rings. Also, it is more closely related to the leek than the onion.
Fortunately, garlic is not an especially difficult crop to grow. Like most garden crops, it requires a pH of around 6.5, excellent drainage, and soil with ample humus. Of the dozen or so varieties grown in Australia, there appears to be only a small number of commercial significance. Italian Purple, also known as Italian White, is the main variety. The cloves of the freshly harvested plant are purple and gradually lose their colour. This is the garlic you will most often find on the supermarket shelf. Mostly imported, but grown increasingly in Australia, are the California varieties, California Early and California Late. They mature before and after Italian Purple. The Early is not a good keeper and both appear to suffer less from Italian's variability in clove size. South Australian White is very late and has excellent flavour. Unfortunately, it is hard to achieve a good bulb size. The individual cloves are small. Japanese, or New Zealand Purple garlic has a small number of very large cloves. It is very early and very strong. Bulb size is large.
Garlic growing in Southern Tasmania Spring 1989
So-called Elephant, Russian or Horse garlic is a type of leek, not a true garlic. It is in almost every way inferior to real garlic, lacks flavour and reproduces itself at the rate of only six to one rather than the fifteen or eighteen to one of the main commercial varieties. Bulb and clove size is enormous.
In the tropics, other varieties are grown, but we have no experience of them. These are varieties developed to not require the winter chilling that triggers sprouting in the varieties mentioned above.
The names given to these various garlic varieties are not their true names, but named after the localities they originated from and their colour. Some varieties have several names and some varieties share a single name.
In order to provide the drainage required, garlic is best grown in raised beds approximately 1-1.2 metres wide and 10 to 20 cm in height. Spacing between plants should be 8-15 cm depending on the richness of the soil. The closer spacing increases yield per unit area, but if an adequate amount of humus and nutrients are not present, bulb size will be too small. While garlic is not graded for size in the marketplace, there is a lower limit to acceptable bulb size.
The footpaths between the beds are best mulched with sawdust, or sown down to a non-invasive grass, such as Brumby Ryegrass. Sprinkling lime on the sawdust breaks it down rapidly, allowing it to be shovelled onto the beds after a few months to improve the soil structure. Weeds that grow through the sawdust mulch are readily destroyed with a wheel hoe.
Well-made compost must be applied to all but the richest soils. The garlic crop will benefit from as much as 2.5 cm of compost.
If trace element deficiencies are suspected, then the addition of seaweed or seaweed meal will improve the growing conditions. A fortnightly spray of seaweed extract, either commercial or home made, may be a cheap alternative. Liquid fish provides major nutrients, as well as the trace elements. It also inhibits some of the fungal diseases that can be problematic in a wet season.
Magnesian limestone, or dolomite is the preferred liming material. Lime should be added to the soil, preferably to a preceding crop, to achieve a soil pH between 6.0 and 7.0.
Where insufficient compost is available, Dynamic Lifter can be substituted. In 1993, a trial using another pelletised poultry manure -- Organic Life -- in conjunction with Humilac Soil and Compost Activator and foliar sprays of Vitec Liquid Fish increased yield by more than 20% compared to compost alone. A mulch of hardwood sawdust top-dressed with dolomite limestone was also used.
In his excellent book, How to Grow More Vegetables (10 Speed Press), John Jeavons of the Ecology Action Group of the Mid-Peninsula (California), reports yields exceeding 10 kg per square metre. He does not state the cultivar, but my experiments and those of another grower, confirm this as an achievable yield. The yield is related to growing surface and takes no account of the space required for footpaths between the beds. Footpaths need to be at least 30 cm wide to allow the use of a wheelbarrow. Where the topsoil is particularly thin, you may care to make your paths wider in order to increase the depth of soil in the growing beds.
The bulbs selected for propagation are the biggest, best and most healthy from the previous crop. The bulb is broken into its constituent cloves at planting time and the biggest are used for “seed”. The size of the clove has an influence on the size of the resultant bulb, so the smaller cloves are rejected. The larger cloves have a bigger food reserve, so they create a larger, more vigorous plant. The individual cloves are then planted at a depth of 2.5 to 5 cm, unmulched. When heavily mulched, the cloves can be planted flush with the soil surface.
Our experiments were conducted using hand tillage. The soil in the raised beds is never compacted by walking on them, or by machinery, so the tilth remains excellent (again given high levels of humus). I use a Canterbury Hoe (claw hoe), my garlic-growing friend a garden fork. Experiments with tilling forks, the U-bar and Gundaroo Tiller are promising. These tools till deeply without inverting the soil and are used every second year. Tillage of well structured soil is very quick.
Joyce Wilkie with an early prototype of her husband, Michael Plane's wheel-hoe
Some users of the raised-bed method, in the United States and in New Zealand, use a tractor that straddles the bed, the tyres remaining in the footpaths (referred to as tram-tracking). The tillage implement is generally a spring-tine harrow or duck-foot plough. Weeding is accomplished with a flame-weeder prior to emergence of the plants and a tickle-weeder afterward. The tickle-weeder consists of many 8-gauge, sprung stainless-steel tines, about 6 cm apart. A hand version of the tickle weeder has been developed and is particularly useful in lighter soils.
Preceding the garlic crop with peas or beans and following it with winter brassicas, followed in turn by summer crops, is an efficient rotation for maximising garlic yield from the area under cultivation. The garlic benefits from the residual nitrogen left behind by the peas and beans, as well as the improved soil structure their roots create. Some growers are using garlic as an insect-repelling interplant. It makes an acceptable companion for almost all crops except peas and beans. Garlic's root exudates suppress the rhizobia bacteria responsible for nitrogen fixation and this effect lingers in the soil for some time after harvest.
The most favourable planting time is autumn, almost immediately after lifting the crop. The longer the crop is in the ground, the larger the yield. The latest I have attempted to plant garlic is October, the earliest, February. The garlic was mature in February and January respectively, only 6-8 weeks difference, despite the 8 month difference in planting times. This is because garlic is day-length sensitive. Planting too close to the longest day can lead to bulbs without separate cloves. Such bulbs are referred to as blind. They make suitable planting material, and in the absence of sufficient “seed”, planting small cloves late will provide seed for the following season.
The garlic cloves will not commence to sprout until they have gone through a chilling phase below 10°C. It appears that a period of one month of chilling is required.
In the absence of chilling, whether by planting into cold ground, or artificial, the germination of the cloves can be quite erratic. If sprouting occurs over a period of weeks, there is considerable lack of uniformity at harvest.
After harvest, the weight of garlic decreases over time as it dehydrates. Also, the individual clove sizes vary. Consequently, the amount required to plant a certain area can only be approximated. As a very rough guide, expect to get 250 plants from a kilo of bulbs.
As soon as the garlic commences to bulb, it is necessary to provide adequate levels of moisture for the process. It would appear unfortunate that this is at the driest time of the year. However, garlic is susceptible to only one disease (in our experience), bulb rot. It is to combat this fungal disease taking hold in the wetter months, that the drainage of the soil be made as good as possible. Of course, unless there is a high level of humus, this would also make the soil droughty. Irrigation when required then, takes place when the atmosphere is relatively dry, allowing the plants to resist fungal disease.
Mulching can be beneficial, but care must be taken to ensure that the mulch will allow the ready infiltration of water. Flood irrigation of the footpaths would negate this potential problem, but that would only be possible on level land. It might necessitate very high beds and as a result large volumes of water. The reason for the requirement for the beds to be very high, is that a well grown garlic plant has roots down to at least 60 cm. On level land in the winter, this could place the roots below the water-table.
When checking soil moisture prior to irrigation, do so at depths up to 30 cm. Avoid the unpleasant surprise at harvest of a bone-dry zone below the surface soil and yield not up to expectations.
So-called leaky hose that is buried in the root zone would appear to offer quite a few benefits. Not the least of these is the low pressure required (3-5 lbs) and the ability to introduce liquid fertilisers with the irrigation water. As well, oxygenation of the root zone is enhanced with a potential for reducing fungal disease.
Mulches we have used include oat straw, hay and green sawdust. The green sawdust is liberally dusted with lime (dolomite), which rapidly decomposes the organic acids in the material, turning it a dark brown. The hay mulch was a failure due to its water repellent property. Water percolates more readily through straw since it is much coarser than hay.
Growing without mulch has been very successful. Following the pea crop, the soil is raked at approximately two week intervals to kill germinating weed seeds. Weeds growing amongst the garlic plants were pulled by hand. The weeds that germinated around December were left to grow in some plots, with no noticeable effect on yield, though they were few and easily controlled, (fat hen, spurry and fumitory).
The garlic is ready to lift somewhat before full maturity. Left too long, the papery skin between the individual cloves starts to break down. The discolouration affects the appearance and marketability. Italian is notably the worst variety in this regard and the harvestable period is said to be only seven days. The garlic commences to make a “flower” and this creates a swelling of the stem, just above the ground. I use this as the indicator for harvest time for South Australian White, though Italian is over mature by this stage. The stem of the garlic becomes quite soft when the garlic is ready and four of the ten leaves have died. The “flower”, when left to mature, turns out to be a cluster of little bulblets, rather than a true flower. I believe that they can be planted to propagate the garlic, but since it takes a couple of seasons to produce a big enough bulb, it is not commercially practicable. Japanese garlic is ready to harvest when the “flower” commences to open. Elephant is ready when the “flower” is fully developed.
Immediately the bulbs have been lifted, cut the roots off with a pair of secateurs, Chinese chicken-scissors or a sharp knife. The roots are tougher when dry. The plants are then left on the ground, or racks, to dry. Bulbs can be scorched by too much sun, so arrange the plants so that the stems cover the bulbs. When the bulbs are bone dry, the stems are cut off and the tedious task of cleaning commences. When the bulbs are truly dry, the outer layer of dirty skin is easily rubbed off. Old woven wire bed-bases make good drying racks.
The bulbs will readily go mouldy if they are stored before they are thoroughly dry. Do ensure that they are. Your customers will not be pleased if they find black, furry spots between the cloves. Approximately 16-18 kg. will fill a standard onion bag, which is the preferred container for storage and transport. In storage, allow plenty of room for the circulation of dry air. The temperature affects storage length and the approach of the warmer spring months sees a rapid deterioration in quality (the cloves commence to sprout). The most favourable temperature range in storage appears to be 10-15°C according to one source. Another says 0°C.
The reason for this disparity is that when the temperature has remained below 10°C for a few weeks, any rise above about 4°C triggers sprouting. Keeping the garlic above 10°C or at 0°C prevents sprouting. Since there are other physiological changes occurring in what is a living organism and they will proceed more rapidly at higher temperatures, then 0°C would appear to be best.
There is a considerable market for the cull garlic bulbs to be sold freshly crushed to restaurants. The cloves should be free of soil and separated from the basal plate where the roots originate. Blend the cloves to a smooth cream in a blender and mixed with a little good quality olive oil. In the refrigerator, the pulp has a storage life of at least 2 weeks.
Australia imports a lot of garlic oil from Japan and other overseas producers. The oil is put up in small gelatine capsules for the health market. Garlic has medicinal properties of considerable repute and was widely used as an antibiotic before the introduction of penicillin. There is little doubt that this market will increase considerably now that antibiotics are falling into disfavour. Whilst penicillin and tetracycline are implicated in the disease Candidiasis, garlic is recommended as part of the natural health therapists cures for the complaint.
Another use for the cloves that are too small to grow on to become sizeable bulbs is to produce spring garlic. This is garlic grown only to the point immediately before bulbing commences. The fresh stems are then harvested, bunched and sold for use in a way directly comparable to spring onions. The white portion is strongly flavoured and the green portion very mild. There is some evidence that the pungent after effects of eating garlic are not so pronounced following the consumption of spring garlic. I have Joyce Wilkie who has a market garden in Gundaroo to thank for this excellent use for the cull garlic cloves.
The rapidly increasing number of farmers adopting organic methods is creating a larger demand for garlic. It is widely used as an insecticide, fungicide, worm drench in livestock, and as a general tonic.
The insecticide/fungicide recipe is:
100 gm chopped garlic
600 ml water
10 ml mineral oil
30 ml liquid (potassium) soap
Steep for 48 hours. Filter and store in a glass bottle. Use 1 part in 99 parts water. This will cover 250 square metres. These figures are a guide only and should be adjusted to suit local conditions, potency of the garlic and other variables. The strict necessity for precise amounts is not so critical as it is with toxic sprays.
Fermenting the green tops of the garlic plants in a conventional beer or wine fermenter with an air-lock has also proved effective. The resultant liquid, when strained and diluted, appears to have a tonic effect as well as insecticidal.
The recipe for worm drench is much simpler. Mix equal quantities of garlic juice and unpasteurised cider-vinegar. For the average sheep, 10 ml should suffice. This information came from Peter Proctor, the New Zealand biodynamic farming consultant.
A quantity of 80-100 ml would be about right for cattle. I used to run a small flock of goats and encouraged them to eat whole garlic plants, which they were reluctant to do, until we bought a goat with an appetite for anything resembling food. The rest of the flock followed her lead.
One farmer using the drench on his cattle made the following observation. He said that when he gave the cows their follow-up drench, three weeks after the first, the cattle were happy to be mustered into the yard for it. He said that when he used conventional drenches, they were most reluctant to go in the yard for their second dose.
Unpasteurised vinegar can be obtained from the Mercury Cider Company in Hobart.
Garlic was widely used as an antiseptic, prior to the introduction of modern antibiotics. The active ingredient is a natural antibiotic called Alliicin. This substance is lethal to a wide variety of pathogenic bacteria, yeasts and fungi. Surprisingly, it is not so lethal to many beneficial organisms, such as those responsible for aiding digestion in the gut. It is superior to modern antibiotics in this regard, as anyone who has suffered the effects of long term antibiotic use will tell you.
On wounds the squeezed juice or a poultice made from the pulp is very effective. Eating the uncooked, crushed cloves is an aid to Candidiasis sufferers and can reduce the impact of the cold virus, as it helps to prevent secondary bacterial infections. Moderation should be exercised with raw garlic consumption, as the sulphur compounds responsible for the aroma and hotness are somewhat corrosive.
There are many recipes calling for garlic as an ingredient. However, garlic is a useful vegetable in its own right. Garlic's flavour varies, depending on how it is treated. Crushing activates certain enzymes that release the sulphur compounds which give the members of the onion family their hotness. Deep frying whole cloves prevents enzyme activity, and the result is an unusual, nutty flavour. Use freshly pulled garlic for this, as the cloves are much easier to peel when green.
To peel the cloves of dry garlic, gently crush the cloves by placing them under the blade of a wide blade kitchen knife, and applying pressure.
The hotness of garlic is exploited in a classic Italian recipe where the cloves are crushed in a pestle with a mortar and mixed with a little coarse sea salt. Spread very thinly on fresh wholemeal bread for one of the world's tastiest treats.
Another Italian favourite is spaghetti con aglio olio. The spaghetti is flavoured with the highest quality olive oil and finely minced garlic. Garlic is best minced with a garlic crusher. There is no need to peel the garlic cloves for this. The skin is filtered out from the pulp.
Whatever you do, avoid the plastic screw-type crushers. The pressure required to crush the garlic rapidly renders these machines useless.
The French and Italian garlic crushers operating on the lever principle and being made of stainless steel are vastly superior.
To make a traditional French salad dressing, mix equal quantities of white vinegar and olive oil. Add a small quantity of minced garlic and freshly chopped parsley and basil. Shake thoroughly immediately before use. While this mixture will keep for some time in the refrigerator, crushed or chopped garlic rapidly alters its flavour. For best flavour always prepare it fresh and consume as soon as possible.
Another French trick is to put thin slivers of garlic between the fell (papery skin) and flesh of a joint of lamb for roasting. The delightful pungency of the garlic totally permeates the flesh.
Many people find the aroma of garlic on the breath offensive. While parsley has the reputation of killing the smell when eaten fresh immediately following the consumption of garlic, I have found it totally ineffective. That does not bother me in the least though, as I care more for the flavour of garlic than I care about what peoples' reaction to it might be.
Hal Huggins, an American dentist, recommends applying neat domestic bleach to the tongue as an effective antidote to garlic breath. In his book, Why Raise Ugly Kids, he recommends Domestos, a common brand of liquid bleach sold in America. However, I have yet to meet anyone game enough to try this simple and probably effective remedy. Bleach is corrosive if swallowed.
Australia imported 780 tonnes of garlic in 1985/6. Australian production was 2,500-3,000 tonnes per annum in the late 80s and declining. Tasmania imports 17 tonnes annually. Imports are rising. The reason for the decline in local production and increase in importation is that conventional agriculture cannot make garlic production profitable. The main reason for this is the high labour requirement. The cost to the employer of employing a person is now equal to, or slightly higher than the wages paid.
Average yield is around 5 tonnes per hectare; 10 tonnes is regarded as good. The potential maximum yield for the hand-tool methods described, is around 60 tonnes per hectare, when 40% of the ground is devoted to footpaths.
I sold my first commercial crop (10 bags) to a fruit and vegetable wholesaler for $A5 per kilo. He told me the price was a little higher than usual that year, because the mainland crop was badly affected by rain.
My two subsequent crops were sold direct to retailers as organically grown and I received $A9 per kilo.
A mainland garlic grower told me that they average a return of $A2-3 per kilo. The wholesale price in Tasmania does not appear to fall below $A6.
Note that imports peak in December, and that this is when the price is at its peak, just before the Australian harvest becomes available.
In the 1990 season, the price offered per kilo by a Melbourne organic wholesaler was $A6-80 per kilo.
The above could be construed as a recipe for making a fortune. Would that it were so. As with most vegetable crops, 50% of your time will be spent in harvesting, cleaning and marketing. Hired labour is not as efficient as the grower's and to justify employing labour requires a quantum leap in production. Seasonal and other conditions can severely affect yields and increasing local production will undoubtedly affect price. The good news is that increasing consumption will, to a degree, offset this problem.
Tasmania's reputation for phyto-sanitary respectability will allow us to export to the rest of the world. The potential for exporting organically grown produce of all sorts to Europe, in the wake of Chernobyl, is enormous. If this booklet has stimulated you to take up growing garlic, I wish you well in your venture.
Importation of garlic and other onion crops in Tasmania now requires a licence.
The author holding a bunch of his garlic
© Jonathan Sturm 2002 - 2011
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