Planting Garlic In Spring: How to Grow Big Bulbs 22 Comments
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.
(1) Garlic Seed
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 they've 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 wouldn't 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.
(2) Cold Exposure
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 don't 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, it's best to plant the bulbs soon after.
(3) Early Planting
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 won't 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.
(4) Good Growing Conditions
Spring planted garlic will almost always be smaller than fall-planted garlic, however, having ideal growing conditions can help minimize the difference. Shelter, fertility and moisture are the most important things you can control.
Choose a location that is protected from the wind, has plenty of sun exposure and warms up quickly in the morning. Using raised beds is also recommended as it helps warm the ground in spring and prevent soggy soil during cold/wet periods in spring.
Make sure the soil is rich in nutrients and especially high in Nitrogen. This fertility is helpful because the garlic plants will need to grow quickly to make up for the lost growing time in fall. Adding compost is also recommended as it will improve the soil's health, however, it may not be enough to meet the fertility needs of the plants. A high Nitrogen fertilizer (organic or regular) applied in spring is often beneficial.
It is also essential to ensure that the garlic has consistent moisture for the entire growing season. Even a week of dry soil conditions can cause stunting of the bulbs and will leave you with a poor harvest. Make sure that plants receive at least 1 inch of moisture per week on loamy soils and 2 inches of moisture per week on sandy soils.
About the Author: John Côté owns and operates John Boy Farms with his family who have been farming the same land for over 140 years. As an agronomist and experienced farmer, he helps others learn how to grow garlic successfully. He has written many articles and is the author of The Master Guide to Growing Big Garlic.
If you have experience or some thoughts about planting spring garlic, Leave a Comment Below! We'd love to hear what you think!