In Canada, garlic is usually planted in the fall as this ensures that the garlic experiences a dormant period through the winter and is exposed to the cold temperatures that many types of garlic require.
Spring planted cloves often do not form a bulb at all and if they do, they are usually much smaller than the fall planted cloves (see our Planting Garlic in Spring article for more info).
In warm regions of the world like California, garlic can be planted in late winter or very early spring easily, however, this is only possible because of their mild temperatures and long growing season.
The best fall planting date for garlic depends mostly on where you live. Your goal is to have the cloves develop as much root growth as possible before winter, without having the clove sprouting and showing green top growth. This means that the date of planting can range from mid-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.
In colder zone 2 or 3 regions such as Western Canada where winter comes early, garlic planting can start as early as September 15 and go as late as the end of October. In warmer regions like southern Ontario, B.C and much of the Northern United States, planting can range from early October until the last week of November.
If you plant your garlic early in the season and end up with some green top growth above the soil line going into winter, it is not the end of the world. The green leaves may die back and the cloves will re-grow new leaves in spring.
On our farm, we like to start planting our garlic the last week of September and try to finish by about October 15th. In our region, this means that the early planted garlic cloves have lots of time to develop large root masses, and the later plantings still have enough time to at least establish some roots before winter.
When possible it is best to make sure that the bulb tips are planted pointed up, and the flat basil plates (clove bottoms) are pointed down. This helps the first leaf emerge out of the ground quickly and grow straight up horizontally. This is more important with hardneck garlic varieties as upside down cloves often form smaller, odd shaped bulbs.
Planting garlic cloves on their sides is another option that can make the process easier and save time. The garlic plants mostly develop normal shaped bulbs, however, some of them will sometimes be slightly misshapen. Softneck cloves tend to be affected the least by side planting and tend to turn themselves upright which allows the bulb to form normally.
Planting garlic in nice straight rows or in a uniform layout is also highly recommended. Garlic tends to require a lot of weeding, and straight rows makes this much easier. Using a string, long stick with markings or a dibbler to indicated perfect spacing helps significantly.
For many years on our farm, we planted all our garlic by hand with the tips pointed perfectly straight up. This resulted in good strong emergence in spring and nicely formed bulbs in the fall. As our operation has grown, we have started to plant more cloves on their sides and have found the majority of them still form very nice bulbs.
Planting garlic cloves on their sides into shallow furrow on clay soil. Cloves can be pushed into the soil further or just covered depending on depth.
Garlic cloves can be planted anywhere from 1" to 3" inches deep. Some growers plant deeper than 3" inches, however this only works well in sandy soils that drain very well. Generally any deeper than 3" is excessive and will force the garlic cloves to use valuable energy when emerging from the soil, limiting the size of the harvested bulbs due to the force of the soil pushing down on the bulbs while growing.
How deep you choose to plant your cloves will depend on a couple factors. One is the type of soil you have and how well it drains. In poorly draining soils like clay, or regions that generally receive high amounts of rain, planting deeper than 1" or 2" can cause the garlic to rot over winter, in spring or during wet periods. In sandy or very well drained soil, planting less than 2" or 3" can lead to drought stress during dry periods.
The second factor is the climate of your growing area. The deeper a garlic clove is planted, the more winter protection it has. In warmer regions like the west coast, winter conditions are mild and depth is not really a concern. In very cold climates like the prairies, planting on the deeper side can help protect the cloves over the winter.
On our farm, we have heavier clay soils and very cold winters. This means that perfect planting depth is very important. We plant our cloves between 1" and 2" depending on the field. At 2" we find that the garlic is usually deep enough to survive the winter, however 1" can easily have winter kill on the more exposed areas without a mulch cover.
There is a wide range of variability when it come to suitable plant spacing for garlic. Cloves can be planted anywhere from 4" to 8" within the row and 6" to 12" between rows, with wider spacing sometimes used to accommodate equipment. How close or how far apart you decide to plant your garlic will depend on how you plan to weed around the plants, your space limitations, the type of garlic being grown and your goals regarding size and quality.
For growers using equipment such as tillers or tractors, the spacing of the garlic has to allow for movement of the equipment through the field or garden. Enough space must be given to ensure that tiller tines or tractor wheels don't hit the sensitive garlic plants or roots even when they are almost full grown. What looks like a lot of space when planting the cloves in fall, often seems too close once the garlic is growing during the summer, so using a wider spacing is a good idea.
Garlic planted in rows 12 inches apart between rows and 6 inches within the row for growing maximum sized bulbs and making weeding easier.
How much space someone has is also one of the biggest determining factors on spacing. If you have limited space to grow, have good soil and want as much garlic as possible, then planting your garlic with very close spacing is the best option. Some of the nicest looking garlic is grown by market gardeners or homeowners that use very intensive beds with extremely tight spacing.
The key to their success is good moisture management, prudent weed control and great soil. If you have a large area or marginal soil conditions, then using a wider spacing is usually a better choice. This will reduce the competition between your garlic plants for water, light and nutrients as well as make your job of weeding much easier.
If you are growing a variety of garlic that tends to produce large bulbs and/or you are trying to grow the absolute largest garlic possible, then giving each plant a large amount of space is the best practice. In general, individual garlic plants do not need a very large amount of space, however using a plant spacing on the wider side will definitely improve your chances of growing large, healthy garlic that looks uniform.
On our farm, we typically plant on 40" raised beds that have three or four rows. In the three row beds, spacing is 12" between rows. In the four row beds, spacing is 10" between rows. All our in row spacing is 6 inches between plants. We have found that our current spacing allows for easy weeding and tends to grow large healthy bulbs.