top of page
GARLIC GROWING GUIDE
The ten stages of growing garlic
Planting is an exciting time in the garden, physically working the soil and starting new beginnings for your garlic crop.
When to Plant
When to Plant
Garlic is generally planted in autumn, with the exact time dependent on your climate and the garlic group you are planting. The saying 'plant on the longest day and harvest on the shortest' is a rough rule of thumb which does not take account climate variations and garlic types. Check out the map and chart below to match your climate to the type of garlic you are likely to grow most successfully. Timing is a fine balance with nature, local microclimates and seasonal variability, and the best timing is not always achieved.
For milder winters garlic is planted earlier and a bit later in colder areas. Garlic needs to be planted to send out roots before being struck with the winter extremes of driving wind, generally drier cooler air and chilling exposure. The strongly bolting hardneck garlics are more hardy in cold climates. Those in extremely cold areas should plant a month before the soil begins to freeze giving the garlic time to grow roots.
Some growers in more mild, humid climates who get persistent garlic rust (a fungi) plant earlier to harvest earlier thus reducing the impact of this fungi in the warmer months when rust can be prolific. Some try growing turban or asiatic garlic which matures and is harvested earlier than other garlics. However by artificially vernalising and planting early plants are more at risk of secondary shooting (witches broom) or results in smaller bulb sizes.
Climate Zone Map
Generally the first garlic to be planted are the semi-bolting garlics of turban, creole and asiatic. These garlics are well adapted to long seasons and milder winters because they are more domesticated.
The strongly bolting garlics of porcelain, rocambole, standard purple stripe, marbled purple stripe, glazed purple stripe and the softneck artichokes should be planted a little later.
Silverskins are the last to be planted in June-August depending on where in the country you live.
Consider the for your climate zone, your local conditions and the type of garlic you are considering growing to decide the best time to plant.
What to Plant
What to Plant
First things first, plant garlic cloves not bulbs - cloves are the divided segments that make up each bulb. The clove skin is not removed. While it is possible to plant the entire bulb, bulbils or true seed (near impossible to find in NZ), the average NZ gardener plants cloves in their vegetable garden. If planting bulbils for the first year you actually plant them at the same time as cloves or you can also plant them in spring as well.
Secondly, cloves are planted with the pointy end up. The stumpy end has the basal plate from which the root buds will begin to swell in autumn ready for planting. Plants will send down their roots from the basal plate deep into the soil in the cold winter months well before any leaf growth comes out of the pointy top end. Cloves planted upside down will grow but are likely to have stunted growth using a lot of their stored energy to find the surface.
Plant only the largest and healthiest cloves. There is a direct correlation between parent bulb size and harvested bulb size. Research suggests there is a ten-fold significance in success in bulb size based on large bulbs compared to large cloves. Also, cloves from a large bulb will generally have a larger harvest bulb compared to the same size clove from a smaller bulb. Interestingly massive bulbs with more cloves have a poorer survival rate. Yet there will always be variation in growing bulbs but consider using large cloves from large bulbs to produce healthy, plump garlic bulbs.
Do not plant cloves from bulbs purchased from a shop that is sourced from beyond our shores. Overseas garlic (you can tell because most supermarkets will state the country of origin and/or their roots will be entirely chopped off) poses a disease risk to our soils. Overseas garlic is normally treated with methyl bromide during fumigation and is also likely to have sprout inhibitors.
How to Plant
How to Plant
Garlic Beds or Pots
Depending on how much garlic you wish to grow and how much space you have, you might need to form a garlic bed. Garlic can also be successfully grown in pots, however avoid plastic pots where possible as it does not permit the soil to breath compared to clay pots. For pots they should be ideally be 50x50x50cm in dimension if growing only a few.
A kiwi typical family (if there is such a thing?) might use 10-20 garlic bulbs per year. Depending on the type of garlic this means a family might need around three bulbs for planting with an average 6-8 cloves per bulb. However, some cannot get enough garlic to eat and might consume 100+/year thus needing at least 10-15 bulbs to divide into 100+ cloves to plant in their garlic bed. Check out the garlic planning diagram to determine how many plantable cloves for each type of garlic.
If you wish to only grow a small number of cloves then you could just find a small pocket in your vegetable garden to poke them in. It is worth putting a few sticks into the soil to delineate where you planted them since they are in for a long time.
If you have a dozen or more cloves then it is worth designating an area as a garlic bed. If growing in a free-draining raised bed there is no need to mound up the soil. If planting into a ground-level bed then consider raising the soil 20-30cm to ensure that the bed does not get waterlogged during the colder winter months or during those spring deluges that occur particularly up north. We grow ours on 30cm mounds, with the troughs for walking between rows filled in using wood mulch.
We make our garlic beds no wider than a metre. This ensures that we can reach all parts of the soil from both sides when planting, applying organic fertiliser, removing scapes and during weeding.
The more space you can give an individual clove the better. Wild garlic origins are from the cold and sparse highlands of Central Asia where there is little competition and thus garlic developed to only grow a few thin leaves. Spacing should allow the plant to maximise exposure to sunlight (> photosynthesis), root mass (> nutrient uptake) and air circulation (< risk of disease such as rust).
The more space you give garlic the more sunlight and uptake of nutrients will occur from the soil. At Gourmet Garlic we have done several spacing trials and found that planting cloves only a few extra centimetres further apart makes a massive difference to plant health and bulb size. If you want to plant just a bulb or a couple worth of cloves then a short row or two can be planted in the garden bed beside other vegetables - keep in mind that garlic leaves can rise up to a metre tall and may shade other plants.
While we are a small commercial grower, like the average home gardener we do not use machinery. Also like the home gardener we would love more room to plant garlic. We plant our garlic cloves 12cm apart with 20cm spacing between rows. This gives us around 40 cloves per square metre. The generally accepted method is 10-15cm apart in rows 15-30cm apart. Ideally, we would like to have more room for them and space cloves further apart (even our trials tell us this) such as 20x20cm apart (25 cloves/square metre) but our garden space just like at home is at a premium. Our pathways between beds are 40cm wide allowing for a narrow walkway between beds to inspect the plants, undertake weeding, and remove scapes.
If you have a lot of garlic to plant consider making a dibble hole jig. The jig will create several holes in the soil at the right soil depth across your row in one go. Ours is simply a narrow strip of wood just over a metre long, with five protruding bolts to make the row. On each bolt we have used a small strip of watering hose as a sleeve between the bolt head and timber. Our spacing and depth are shown in the diagram below.
The depth to plant cloves depends on your climate zone and the size of the clove. Those with mild winters barely have to poke the clove into the soil. This would mean the top of the clove sits only a couple of centimetres from the surface.
Those with cool winters should plant with 2-5cm of soil on top. In cold climates, it is suggested to plant cloves 5-7cm below the soil surface to protect the clove from the winter extremes and to reduce the chance of frost heaving the clove to the surface. If the clove is large then consider placing it slightly deeper to allow for the longer length of the clove. It is not an exact science. Generally the top of the clove should have a covering of at least 2cm.
If your soil is light then you might also sow deep as the roots have a tendency to push the clove upwards during winter and exposed them at the surface. If this happens carefully dig a minor pit beside the clove and put the clove deeper without disturbing the roots.
This is a simple process. Make the holes for the cloves to the relevant depth. You could use your index finger to make hole and pop the clove in or use a jig. Ensure that the soil is moist, otherwise it will dry out the clove hampering growth and germination. Take a clove from an earlier cracked bulb. Holding the wider base, place the clove into the hole with the pointy end up. Once a row is completed gently apply soil to cover the holes.
Early harvesting garlics like turban and asiatic garlic will take about a 1-2 weeks to show leaves, while mid-late harvesting garlics could take six weeks as they rely on cold soil temperatures to trigger leaf development. You can always check root and leaf development by gently digging down in the soil to check.
bottom of page