The majority of garlic grown in North America is planted from the beginning of October through November, a few weeks before the ground freezes. At Calling Quail Farm in southern British Columbia, we begin planting between the first and the 15th of October. The best way to judge the correct time to plant garlic in your region is to observe when other local growers plant, and follow accordingly. If you are curious and have cloves to spare, try planting over successive weeks in clearly demarcated zones and compare the size of your bulbs at harvest to determine which weeks of planting produced the best bulbs.
The aim of this timing is to provide the garlic with enough time to put down roots but not enough time to significantly sprout. Although the cloves begin to grow soon after you put them in the ground, they require a period of cold to encourage vernalization, which is an interval of dormancy essential for successful development. Garlic, after a small period of growth, goes through this crucial state of dormancy when the ground becomes suitably cold, before resuming normal growth in the spring. Garlic that does not have a sufficient period of vernalization will often fail to thrive, producing small bulbs or even bulbs that have not differentiated into separate cloves. Different cultivars require different degrees of vernalization, however, the standard winter season is sufficient for all types.
In climates with either very severe or very warm winters, growers may plant in January, February, or even later, into the spring. Garlic planted in the spring still needs a period of cold dormancy for proper growth and to achieve this, growers induce vernalization by storing their seed stock in cold storage between 4°C and 10°C (40-50°F). The prescribed time for different cultivars may vary, but a holding period between 2 and 6 weeks is considered sufficient¹. Once removed from storage, the cloves are planted and should promptly begin to sprout. Spring-planted bulbs are often harvested at the same time as fall-planted garlic, although you will need to evaluate the maturity of your own garlic to determine whether the bulbs are ready to be harvested.
Prior to planting, ensure that your soil is well prepared. Soil preparation is essential both to promote growth of the garlic plants and to protect them. One recommendation is to cultivate your plot several times. Cultivation will loosen and aerate the soil, help you phase out weed seed, and allow you to confirm that the soil is healthy.
Garlic is a fairly hardy plant, growing in conditions where other plants often fail. Even so, it is a good idea to add organic matter such as compost or manure to your soil before planting to give it a boost. Conducting a simple soil test is helpful in determining if your soil is deficient in any nutrients. Although garlic does not consume nitrogen as voraciously as some plants, it does prefer soil rich in nitrogen. Phosphorus is also important for healthy root growth, and if lacking, should be added prior to planting.
If you are planning to plant garlic every year, a crop rotation system, where practical, is ideal. Crop rotation helps prevent the accumulation of disease and pests that could negatively impact your garlic and also helps to replenish lost nutrients. The recommended system for garlic is a three-year rotation, but this is not always realistic for growers with limited land. If a three-year rotation is not possible, try to alternate your garlic crop at least every other year. During the alternate years, plant crops that will both replenish and provide a practical benefit, for example, squash, melons, and corn, which can be eaten or sold.
Further soil preparation can vary significantly between regions, so confirm what type of soil you have and how to best prepare it. Garlic prefers loose, loamy soil with good drainage, however, you simply may not possess this type of soil so any preparatory measures you take will be well worth the effort to ensure you maximize the size of your bulbs. Once your soil is prepared and you have estimated a likely date for planting, the next step is to “crack” or “pop” the bulbs, which will be discussed in my next blog, Growing Gourmet Garlic: Planting Part 4 – Cracking and Clove Selection.
Andrea Cross grows gourmet garlic at her farm, Calling Quail, in British Columbia, Canada. She also has a personal blog at callinquailfarm.tumblr.com/, a farm website at www.callingquailgarlic.com/ and Facebook page www.facebook.com/CallingQuailFarm
Want to read the other parts in this series? Check out:
Growing Gourmet Garlic, Part 1: Where to Get Seed and How Much to Plant
Growing Gourmet Garlic, Part 2: Choosing Which Bulbs to Plant
Growing Gourmet Garlic, Part 4: Bulb Cracking and Clove Selection
Growing Gourmet Garlic, Part 5: Spacing, Planting and Mulching