There are two main kinds of garlic. (Actually, there are three. The third kind, ‘elephant garlic’, Allium ampeloprasum, has absolutely enormous cloves, but has no garlic flavor worth mentioning.) The first is ‘Common garlic’, which is the usual white skinned supermarket type plus the silverskin types generally used for braiding and available at farmers markets; and ‘Hard neck garlic’, which is much less common.
Common garlic Allium sativum – Soft neck Garlic, Italian Garlic, Silverskin Garlic. There are two main ‘types’ of common garlic – the so-called ‘artichoke’ garlics we buy in the supermarket, and the ‘silverskins’, with either very white, or white blushed rose outer skins. The bulbs of the common ‘artichoke’ types outer parchment is white, or off-white. There is usually a row of decent sized cloves around the outside, and irritatingly smaller, thinner cloves in the interior (altho’ there are varieties with few, but quite large, cloves). As we all know, removing the skin from these cloves is not easy. The bulb is wrapped in many layers of parchment, which continues up to form a soft parchment like neck ideal for using to braid all your bulbs together on a string to hang in the kitchen!
This garlic keeps well. Silverskins have the strongest flavor, and have numerous small cloves. They are very white, and the neck is sturdy and well suited to plaiting. The ‘Creole’ sub-group of the silverskin type is atypical, because they have only 8-12 cloves, are mild, and have a rose colored outer skin.
Hardneck Garlic Allium sativum var.ophioscorodon – Serpent Garlic, Stiffneck garlic, Rocombole Garlic, 10 clove garlic, Top Setting Garlic, Bavarian Garlic, Porcelain Garlic, Purple stripe garlic.
These garlics have a stiff, sometimes thick, neck, usually with fewer, even sized cloves arranged around the central ‘neck’. Cloves number from four to twelve or so, depending on the variety. They are generally less reliable in changeable weather conditions than soft necked garlics, with the exception of the rocombole type.
The most distinctve of the three main hardneck types is ‘Rocambole’ Garlic. This garlic is similar to common garlic, but has two important differences. First, unlike common garlic, it throws up a flowering stem, called a ‘scape’. Second, the bulb has relatively little outer parchment. This last difference has a positive and a negative side. On the negative side, the individual cloves are often exposed, can be knocked off the bulb by rough handling, and can wither a bit after long storage. In addition, the bulbs don’t look anything like as attractive as bulbs of common garlic. On the positive side, they are a dream to remove the skin from -it is trivially easy- there is only one ring of decent sized cloves arranged around the woody central flower stalk and no smalls or thins, and it keeps almost as well as common garlic if stored carefully. The tall flowering scape , for reasons of its own, makes a twisting loop as it unfurls it’s ‘flower’ head (which contains not flowers, but tiny little bulbils). Thus it’s alternative name, ‘serpent garlic’. Clipping the flower stalk off early on significantly improves bulb size.
It needs a cool winter and spring, and simply will not suceed in hot areas.
Purple Stripe Garlic has very white, thick, bulb skins, streaked with bright purple. They are quite a variable group, with some strongly flavored, some mild, some mid season,some late maturing. They store fairly well.
Porcelain Garlic includes varieties with few (4-8), large fat cloves covered in a very thick, very white bulb skin. The taste is usually strong. They store moderately well if free of disease.
Be guided by local varieties. But make sure they genuinely are local! But even within a broad climatic region, there is sometimes enough climatic variation with such ‘micro climate’ influencing factors as altitude, proximity to the sea, mountain rain shadow effects, and so on that a variety that is reliable in one location may be marginally reliable in another. Advice of knowledgeable local home gardeners may be the key to variety choice.
California Early and California Late need cold exposure of around 6 weeks below an average of about 4C/40F for proper bulbing and clove development. It is the classic, white skinned garlic ‘artichoke garlic’ of the supermarkets.
New York White (syn.Polish White) White parchment, slightly blushed with purple, said to be relatively disease tolerant, and better adapted to temperate than warm temperate areas.
Creole This silverskin garlic is quite a late maturing variety from Central America ( also grown in the Imperial Valley of California). It is adapted to heat and dry conditions, and doesn’t do well in more humid and cooler areas.
The cloves have a deep purple skin.
German extra hardy A hard neck garlic with a white outer parchment and red skin on the cloves. Noted for it’s vigor, strong resistance to winter heaving in temperate areas, and good storage ability.
Roja A fairly common home garden rocambole type with attractive, brownish-red, medium-sized bulbs.
Continental garlic Is more of a generic term covering various white or purple striped hard neck types adapted to more Mediterranean growing conditions.
Prepare the soil
Ideally, a deep, fertile, very well drained soil is needed. Add -and incorporate well-a good dressing of a general garden fertilizer before or at the time of sowing. Your soils pH must be above 6.0.( Ideally, pH 6.5 -7.0). Unless you are on limestone country, most soils will benefit from a liming at least a month or so before planting. Lots of well rotted compost is beneficial, if you can get it.
When to sow
warm temperate areas – generally speaking, it can be planted in autumn through to early winter. Under warm temperate climatic conditions autumn planted garlic will remain dormant for a few weeks, then develop roots and a shoot. With the onset of the cold of winter growth is fairly slow until temperatures warm in spring. The cold of winter is needed to initiate the side buds that will ultimately grow and swell to become cloves (and in some types, to initiate the flower bud). The lengthening days of spring are the signal for the initiated but undeveloped side buds to start forming into cloves. It is possible to sow in early spring and get a reasonably good harvest, but everything is against you – wet, difficult to work soil; no early root growth; less exposure to winter chill. Early Spring is possible, but definitely a second choice.
Temperate areas- plant after the first good frosts of autumn. Spring planting is possible in the higher latitudes, as the longer day lengths promote bulbing, but the shorter season means the bulbs are often smaller. Autumn garlic will produce roots, but either no, or short, top growth. If the garlic sprouts have emerged, they will survive freezes and snowfalls, but they should be mulched heavily (about 15 cm/6 inches) to prevent heaving. Pull the mulch aside in spring. Autumn planted garlic will have strong roots by winters icy grip, and these roots will help prevent the ‘seed’ being pushed out of the ground as the soil alternately freezes and thaws (‘frost heave’).
How to sow
Choose the biggest and fattest seed cloves, and sow them root end down, standing erect, and far enough in the soil that they are anything from just buried to being 25 mm/an inch or so under the soil surface. Put them about 100 mm/4 inches apart.
The tricks of growing satisfactory bulbs
Home grown garlic can be disappointing- small bulbs, bulbs with only one big soft clove, no bulb. The causes of unsatisfactory production come down to the quality of the ‘seed’, growing conditions, the variety, the vagaries of the season, and disease.
give the best possible drainage
It is important to have a free draining soil. While cloves put in early in winter will have a longer cold treatment and will respond to lengthening days more quickly than those put in later, there is always a risk of the cloves rotting in a cold wet soil. Especially if the cloves are of dubious quality, or if you have a history of disease problems in your own saved seed cloves. Commercially, the seed cloves are often soaked in rugged fungicides prior to sowing to minimize this problem, but this is not an option for most of us. Excellent drainage is very important to give the edge on climate and disease.
give your plants an unreasonable advantage
Your garlic is likely in a race against root rotting disease and stem and leaf diseases. The better the leaf growth before bulbing starts, the bigger the bulb and the cloves will be. This translates to ‘early care pays dividends later’. And also at the main growing stage, give your garlic every advantage to grow more than the disease will damage. Provide a free draining soil by amending it with sand, potting mix, well finished compost, leaf mould, or whatever. Consider a raised bed, or large tub culture. Before sowing, beef up the nutrient status of your soil by working in a complete fertilizer (5N – 10P – 10K) at about 225gms/half a pound per 7.5 Metres/25 feet of 30 cm/12 inch wide row. Once they have started growth in spring, give them regular – say fortnightly – very light side dressings of urea (or other high nitrogen fertilizer), spread 100 mm/6 inches either side of the plants. Liquid manures are also beneficial. Garlic competes poorly with weeds. Keep them as close to meticulously weeded as is possible. Be careful with the hoe- there is nothing more tragic than a beautifully growing garlic plant sliced off at soil level by a hurried hoe! If the weather is dry, mulch them to conserve water. Dry soil when the leaves are developing affects the yield quite badly, so water them well and regularly in dry periods.
either buy clean seed stock or provide ideal growing conditions
If you grow garlic regularly, and especially if you keep your own seed cloves, you will almost inevitably end up with a greater or lesser degree of disease in your soil and seed stock. This shouldn’t prevent you from growing garlic, be we do need to accept that we have to put extra effort into keeping the plants in best possible condition when they start growing, and accept that is very wet years we may lose the lot. Even if you have disease in your soil, it is probably best to by clean seed cloves every year, as they will get a good start before becoming infected. Rocombole can usually be relied on to produce something, even when your common garlic is a total loss. Garlic that is water stressed in it’s early growing period can ‘re-vernalise’, which means the plant in effect ‘cancels’ the side buds that were about to grow into cloves, and produces a single fat, low quality clove instead. Cold winters largely prevents this phenomenon, so it is chiefly a problem for warm temperate areas. The same thing can happen if the plant is exposed to unseasonably high spring temperatures-29C/85F or above. The solution is keep the garlic well watered if there is a dry spell in spring, mulch to keep the soil, at least, cool, and keep your plants growing strongly.
use the most suitable variety
Some garlic strains will just not bulb satisfactorily in your area. Garlic varieties are adapted to a fair range of day lengths, intensity of cold, and accumulated heat conditions. Don’t expect all varieties to do well in your area. ‘Wrong’ varieties may grow very well, but not bulb properly, re-growing from the barely formed new season cloves without the top dying back and without forming a proper bulb at all. Try locally sold seed cloves. They may well be- but certainly not certain to be- the best variety for your climate. In mild and cool climate areas ‘rocombole’ garlic is far more forgiving of the vagaries of climatic conditions than common garlic. Equally, in hot areas, the ‘creole’ silverskin types are far more reliable than most other garlics.
The plants are ready to harvest when the foliage has died off, or mostly died off. If it is very wet near harvest time, consider lifting them a bit earlier and drying them under cover. Left in wet soil, the outer parchment often rots. And if there is disease in the root plate, it may develop too far and cause the bulb to fall apart when it is lifted. Rocambole is almost always ready to harvest a month or so before common garlic. But the state of the foliage is the indicator, not any particular date. An experienced Italian American home garlic grower passes on a valuable tip for refining the estimate of when to harvest common garlic-
“Once the top part of the plant has begun to turn brown, pull one of them and peel back the sheaths one at a time. My grandfather liked to wait until there were 2 sheaths, but I’m more comfortable with 3 to 4 sheaths. The problem with only watching the top part of the plant is that when it’s very wet or very dry, the sheaths can reduce much faster than in other years.
For example, it was very wet this year in Pittsburgh, PA, where I live and garden. The plants had just started to turn brown when I checked the first one. It was already down to 3 sheaths!!! You might want to warn people what happens if they wait too long – the garlic opens up and it’s nearly impossible to get out of the ground. (And the garlic you do find is already starting its growth cycle, so it doesn’t keep.)” – RC, Pennsylvania. USA
Wash the bulbs, especially the roots, and leave them for a week or so to dry- so long as it is fine. If you live in a hot climate area, you will have to dry them out of the sun, or your precious bulbs will sunburn. If the weather is dubious, dry your garlic under cover. When the bulbs are dry, you can trim off the roots, scuff off the outer discolored parchment, and braid your garlic for storage.
If you intend to keep your own clove seed, select the biggest and best bulb. Leave the cloves on the bulb, and at planting time select only the best cloves to use as seed cloves. But store your seed bulbs in a relatively cool, dry place-heat in storage can cause the seed cloves to develop into a plant that produces a single large clove , rather than a normal multi clove bulb. Prolonged very low temperatures can also disrupt proper growth.
Store garlic in a dry place- the kitchen is OK, and towards autumn (if there is still some left!) check for soft bulbs (rotting internally), and sign of insect damage. Throw out damaged bulbs. The ideal storage conditions are temperatures of around 10C/50F, dry, and well ventilated.