Many gardeners like to get a head start on the growing season by planting garlic in spring. However garlic is traditionally planted in fall since the cloves require a cold treatment known as vernalization before sprouting. This cold period mimics winter conditions and encourages proper growth and bulb formation.
When planting garlic in spring the cloves miss out on the natural vernalization that would occur when left in the ground over winter. So for best results spring-planted garlic may need to be pre-treated in cold conditions before planting. A common question is whether putting garlic in the freezer can provide the cold exposure needed.
Why Garlic Needs Vernalization
Garlic is a biennial crop meaning it takes two years to complete its lifecycle from clove to mature bulb. The first year, the planted clove produces vegetative leaf growth and roots. It does not form a bulb.
The second year, after exposure to cold winter temperatures, the clove sprouts again, producing a flowering stalk (scape) and bulb. The cold period allows the plant to transition from vegetative to reproductive growth.
This cold requirement prevents the garlic from sprouting in fall and being damaged by winter conditions. It ensures the plant waits until the next spring to send up new growth.
When garlic is planted in spring, it misses out on this cold vernalization period and may not form proper bulbs or cloves at harvest. The foliage simply keeps growing in a vegetative state rather than switching to reproductive bulb production.
Using Refrigeration to Vernalize Garlic
To mimic winter cold and vernalize spring-planted garlic, the cloves can be pre-treated by storing in cold conditions before planting. Refrigeration at temperatures between 32-50°F (0-10°C) for 4-8 weeks is commonly used.
The refrigerator provides consistent cold but above freezing temperatures that signal to the garlic it’s time to prepare for spring growth. Keep the cloves in a breathable bag or container and out of the crisper drawer.
Check frequently that sprouting hasn’t started yet. Plant the pre-chilled cloves as soon as possible once removed from refrigeration. The goal is to properly vernalize the garlic while preventing it from actually sprouting before planted.
Is the Freezer Too Cold for Vernalizing Garlic?
Home freezers are typically set to 0°F (-18°C) or below. These very cold temperatures can damage cloves rather than properly vernalizing them. Freezing may kill the growth point of the clove or harm the embryo before it has a chance to grow.
One study tested storing garlic bulbs for up to 8 weeks in -4°F (-20°C) temperatures before planting. Nearly half the cloves showed damage from the freezing temperatures after 8 weeks of storage.
Shorter durations of 2-4 weeks had less impact on viability but did reduce sprouting and growth compared to unfrozen controls. The researchers concluded that storing garlic at -4°F or below causes injuries that inhibit plant development.
While refrigerator temperatures provide ideal vernalization, freezer temperatures seem too extreme for pre-treating garlic effectively. The very cold can harm or kill the cloves. Even at slightly warmer freezer temperatures around 15°F (-9°C), damage is likely over extended durations.
Other Ways to Vernalize Garlic for Spring Planting
If storing garlic in the freezer doesn’t seem advisable, here are a couple other vernalization options for spring planting:
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Plant very early – In areas with very cold winters, planting the garlic cloves very early in spring while ground temperatures are still freezing provides natural vernalization. Ensure the soil is workable and not frozen solid before planting.
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Outdoor cold exposure – Keep the bulbs or separated cloves in an unheated garage, shed, or buried in the garden over winter. This exposes them to natural chilling hours. Check frequently for sprouting or rotting.
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Buy pre-chilled garlic – Some garden centers and nurseries sell “spring garlic” that has already been pre-treated and is ready for early spring planting.
With the right vernalization treatment before planting, you can fool your spring-planted garlic into forming nice big bulbs in time for summer harvest. Just avoid prolonged freezer storage, as the extreme cold can kill cloves rather than vernalizing them properly. Stick to refrigeration or early spring planting for best results.
Growing Big Spring Garlic Bulbs
Here are some other tips for a successful spring garlic crop:
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Choose large cloves – Large cloves have more energy stores to fuel growth. Size matters!
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Plant early – Don’t wait! Plant the pre-chilled cloves as soon as the soil can be worked in spring.
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Choose varieties suited for spring planting – Softneck, Creole, and Silverskin types need less vernalization than hardneck garlic.
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Provide plenty of sunshine – At least 6 hours per day. Morning sun is ideal.
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Use raised beds – Improves drainage and warms the soil. Prevent soggy conditions.
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Add organic matter – Mix in compost and aged manure to enrich the soil with nutrients.
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Fertilize – Use a nitrogen-rich fertilizer at planting and again when shoots are 6 inches tall.
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Mulch – Once sprouted, add 3-4 inches of straw or leaves to retain moisture and heat.
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Ensure consistent moisture – About 1-2 inches of water per week. More for sandy soils.
Follow these tips and your spring-planted garlic should grow large, healthy bulbs. Just leave the freezer out of your vernalization plans!
Spring or Fall
Many gardeners do their garden planning during the winter or very early spring. This process includes looking through all the seed catalogues and deciding what they will be planting for the coming season. Sometimes, this includes wanting to plant garlic in spring even though it is not generally the best time of year.
In cold climates like Canada and the Northern United States, most garlic is planted in the fall because the plants require a natural dormant period that includes exposure to cold temperatures (vernalization). When planted before winter, the garlic puts down roots until the temperatures freeze and then waits until the next season to continue growing. This fall growing period allows the garlic plants to get a head start and then explode out of the ground once temperatures warm up in spring.
Although garlic is ideally planted in the fall, it is still possible to grow and harvest beautiful bulbs if you miss planting before winter. The following tips are the most important things to remember when planting garlic in spring and trying to grow big bulbs.
In general, planting the largest seed cloves possible helps produce big bulbs at harvest. This is especially true for spring planted garlic that will have a shorter growing period than fall planted garlic. The extra energy stored in the larger cloves helps the plants send out strong roots and leaves that explode out of the ground early. This early growth gives the plants a jump on the season and will result in a larger plants with greater ability to develop a large bulb later in the season.
One of the challenges for many growers is finding spring garlic bulbs to plant in the first place. Most garlic varieties offered by seed companies (including our farm) are only available in late summer or fall. However, you can often purchase “spring garlic seed” at garden centers or greenhouses. This garlic is often a softneck garlic and does not need very much cold exposure. That means that the bulbs can usually be planted right after theyve been purchased. For hardneck varieties, which are becoming more common in spring, some cold exposure will probably be required before planting (more info below).
Regular food garlic you find in the grocery store is generally a very poor source of seed for planting. The bulbs are often treated to prevent sprouting, can be up to a year old and have a high risk of carrying viruses or diseases that most growers wouldnt want to introduce into their soil. As well, almost all commercial garlic is grown in warm regions like California or China. If you live in a colder climate, these “warm season” varieties are not well suited for growing.
If you are planting a hardneck variety in spring and you want them to form bulbs at harvest, the cloves will need cold exposure for proper growth (softneck garlic can also benefit from some cold exposure). This can sometimes be accomplished by early spring planting when temperatures are still extremely cold. However, this does not always work and it is best to expose the garlic to cold before planting (some store purchased bulbs have already been exposed to cold so this step may not be required).
Without vernalization, some garlic plants will not form bulbs properly, producing single clove bulbs called rounds. These rounds are perfectly good to eat and can be replanted in fall with success. They should develop good-sized bulbs with multiple cloves the following summer. Also, some growers like to harvest their spring plantings as green garlic well before bulbs form and therefore dont require any cold exposure.
The ideal temperature for vernalization is 0 to -3 degrees Celsius when trying to vernalize or “trick” the garlic cloves into thinking they went through winter. This process can be challenging without the help of mother nature, although refrigerator temperatures (usually 1 to 2 degrees Celsius) can also work.
Proper vernalization can be accomplished by placing the garlic in a refrigerator (as cold as possible) for at least 2 to 3 weeks. The longer the period of cold exposure is, the stronger the effect. That means that when time allows, a more extended period of up to 2 months in cold storage can be beneficial.
If using refrigeration for vernalization, it is important to remember that it can dehydrate the garlic over a longer period. Some growers place the garlic in a plastic bag (sometimes with holes for ventilation) to prevent excess drying. This often works well, however, you must keep an eye on the garlic to make sure it does not develop mould, rot or start sending out roots. If the roots start growing, its best to plant the bulbs soon after.
Another important strategy is to plant spring garlic as early as possible. That means planting the garlic cloves as soon as the soil is workable and long before you would consider planting any other garden crops. Even if the forecasted temperatures are for extremely cold spring weather, the cloves should still be planted. Garlic plants are very cold hardy and can tolerate temperatures well below freezing.
Garlic is sensitive to day length changes and not having enough days with increasing day length can affect whether or not there is the formation of cloves within the bulb. That is why planting garlic too late in spring will often form rounds, just like cloves that have not been vernalized properly.
Another factor to consider is that warm temperatures increase the rate of bulb formation, meaning that the garlic can mature too quickly. Garlic planted too late in spring wont have enough time to develop large bulbs before the hot weather arrives and the plant starts to shut down for the season. Yes, the garlic will have cloves, however, the bulbs will be very small.
In northern regions like Canada and the Northern United States, this usually means it is best to plant by early May and in warmer locations like the southern United States, no later than March.
Planting, Growing, and Harvesting Garlic
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You can grow your own garlic! Before you plant, know which garlic variety matches your climate and cooking. We’ll also share tips on how to grow bigger bulbs. Learn all about planting, growing, and harvesting garlic and garlic scapes.
A nickel will get you on the subway, but garlic will get you a seat. –Yiddish proverb
Planting GARLIC in SPRING after being kept in the Freezer
FAQ
Should I put garlic in the freezer before planting?
It will definitely work. I would recommend putting it in the fridge to encourage sprouting at about the 3 weeks prior to planting stage, if you can afford the space. The cold temps of just above freezing are perfectly horrible for storing garlic because they initiate the development of the cloves to sprouting.
How long does garlic need to be cold before planting?
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Why the cold period is important:Garlic, especially hardneck varieties, needs a period of cold temperatures to trigger the development of individual cloves within the bulb. Without this, the garlic may develop into a single, large bulb instead of the desired cloves.
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Fall Planting:The most reliable time to plant garlic is in the fall after a hard frost. This allows the garlic to establish its root system before the cold weather arrives.
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Spring Planting:If planting in the spring, you can simulate the cold period by placing the garlic cloves in the refrigerator for about 40 days before planting. You can also plant garlic in early spring, ensuring it gets enough cold exposure before the warmer weather sets in.
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Timing in Los Angeles:In Los Angeles, with its milder winters, it’s still important to plant garlic in the fall to get the necessary cold exposure. Fall planting in Los Angeles, between October and November, gives the garlic time to develop a root system before the colder weather arrives.
Do you need to put garlic in the fridge before planting?
Plan ahead for when you want to grow garlic. Chill garlic cloves in the fridge for a few weeks before planting. This improves bulb development. You can skip this step but it helps grow bigger garlic.
Can frozen garlic be planted?
Garlic can be planted into frozen ground and usually does well.
Can you plant garlic in the freezer?
If storing garlic in the freezer doesn’t seem advisable, here are a couple other vernalization options for spring planting: Plant very early – In areas with very cold winters, planting the garlic cloves very early in spring while ground temperatures are still freezing provides natural vernalization.
How do you plant garlic?
To plant garlic, start by separating the garlic bulbs into individual cloves, leaving the papery layer around each clove intact. Choose the largest cloves for planting and use the smaller ones for cooking or preserving. Dig holes in the ground that are around 2 to 3 inches deep to plant your garlic cloves.
How should you store garlic for planting?
To store garlic for planting, keep it at 30°F (-1°C) in a well-ventilated area with 65-70% humidity. Cure the bulbs, check for damage, and select the biggest cloves. When stored properly, garlic will stay good for 9 months.
Should garlic be planted in winter?
This cold period mimics winter conditions and encourages proper growth and bulb formation. When planting garlic in spring, the cloves miss out on the natural vernalization that would occur when left in the ground over winter So for best results, spring-planted garlic may need to be pre-treated in cold conditions before planting.
When should you plant garlic?
Plant garlic as early as possible. If you live in an area where the ground thaws in early spring, you can cold treat garlic by planting it outdoors as soon as the soil is workable. If your soil doesn’t thaw until late spring, plant garlic in weather-proof pots instead, and put those cold-hardy cloves outside while it’s still cold.
What should you not do when storing garlic?
Never store garlic in air-tight containers or the cloves will rot and mold. Properly stored garlic stays good for up to 9 months. Put garlic in the fridge for 3 weeks before planting if your winters don’t get cold. In areas without cold winters, stick the garlic in the fridge for 3 weeks before planting.