When to Plant Garlic in Canada
In Canada, garlic is usually planted in the fall so that cloves are exposed to the cold temperatures (vernalization) that many types of garlic require. Garlic can be planted in spring, however, the plants often form single cloved bulbs (called rounds) or they grow normal bulbs that are much smaller than fall planted cloves (see our Planting Garlic in Spring guide for more info).
The best fall planting date for garlic depends mostly on where you live in Canada. Your goal is to plant early enough to have the cloves develop a large root system, while at the same time planting late enough that garlic cloves don't sprout and show significant green top growth above the soil.
This means that the date for planting can range from the middle of September to as late as the end of November depending on where you live and how long you want your cloves to settle in before winter. Garlic can technically be planted right up until the ground freezes, but the ideal time is about 4 to 6 weeks before this happens.
In colder zone 2, 3 or 4 regions such as Western Canada, Northern Ontario and Northern Quebec where winter comes quickly, garlic can be planted as early as September 15 or as late as the end of October.
In warmer regions like southern Ontario, coastal British Columbia and the Maritimes, planting can range from early October until the last week of November.
If you plant your garlic early in the season, you can sometimes end up with a small amount of green top growth above the soil line going into winter. These first green leaves may die back if they are exposed to extremely cold temperatures, however, the cloves will re-grow new leaves in spring and the garlic won't be harmed.
A garlic clove that was planted early and emerged from the soil before winter. Notice the slight tip burn at the end of the first leaf.
Garlic cloves can be planted anywhere from 1 to 3 inches deep (top of clove to soil surface) and the roots will continue to grow as long as the soil is not frozen.
The deeper garlic is planted, the longer it will take for the soil below the cloves to freeze. This means that deeper planted garlic will usually have a slightly longer time period for its roots to continue growing before the ground completely freezes.
For growers planting towards the later part of the planting window, slightly deeper clove depth often helps give the roots more time to fully mature before winter.
Most growers in Canada mulch their garlic for the winter protection. Mulching helps moderate soil temperatures and keeps the cloves protected from fluctuating temperatures.
Mulching also keeps the ground from freezing until the coldest temperatures of winter arrive. The mulch forms a blanket that keeps the ground heat from escaping, thus keeping the ground warmer. This means that by adding a thick layer of mulch (such as straw) over garlic beds, it is possible to extend the growing season in fall. The mulch cover with allow the clove roots to continue growing into late fall and early winter even though the outside temperatures have fallen below freezing.
Thick mulch also protects any garlic leaf sprouts that have prematurely emerged in fall and often prevents them from dying back to the ground level over winter.
Wheat straw is the most commonly used mulch and should be applied at least 4 to 6 inches (10 to 15 cm) deep directly over the planted garlic. Other types of mulch such as oat straw, barley straw or hay can also be used.
In early spring, some growers remove the mulch completely once the threat of extreme cold is gone. Removal helps warm the soil once the snow melts, minimize disease during wet weather, and make weeding easier during the growing season.
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.