If you have never grown garlic before, this is the year to start. And September is exactly the right moment to be thinking about it.
Garlic is one of those crops that seems almost magical the first time you grow it. You tuck a single clove into the ground in October, mulch it well, largely forget about it through the winter, and come back the following July to pull up a full, fat, papery bulb of homegrown garlic that tastes incomparably better than anything you have ever bought at a grocery store. The work is minimal. The payoff is enormous. And once you have grown your own garlic, you will find it very difficult to go back to the pale, flavourless imported bulbs that fill the produce section eleven months of the year.
The catch, and it is a small one, is timing. Garlic is a fall-planted crop in Ontario. It goes in the ground in September and October, overwinters underground through our Zone 6a freeze, and is harvested the following summer. The planning and purchasing decisions you make right now in September determine what comes out of your garden next July. Miss the planting window and you wait another year.
Here is everything you need to know to plant garlic successfully in Ontario this fall.
Why Garlic Is Planted in Fall, Not Spring
Understanding why garlic is planted in fall makes the whole process make more sense and helps you time it correctly in your specific Zone 6a garden.
Garlic needs a prolonged period of cold temperatures, called vernalization, to develop properly. This cold period triggers the biological process of bulb formation that allows a single clove to develop into a full multi-clove bulb the following summer. Without adequate cold exposure, garlic plants produce a round, undivided bulb called a "round," which is edible but not the full bulb you were expecting and not what you wanted to grow.
Ontario's Zone 6a winter provides exactly the cold period garlic needs. Cloves planted in fall put down roots through September and October before the ground freezes, go dormant through the coldest months of winter, and resume vigorous growth as soon as soil temperatures begin rising in March and April. By July the plants are ready to harvest as fully formed, flavourful bulbs that have been quietly building underground for nine months.
Spring-planted garlic is possible in Ontario, but the results are significantly inferior to fall-planted garlic in virtually every measurable way. Fall planting gives garlic the full cold period and the maximum growing season it needs to develop the largest, most flavorful bulbs possible. Fall planting is simply the right way to grow garlic in Ontario.
Hardneck Versus Softneck: Which Garlic to Grow in Zone 6a
This is the most important decision you will make as a garlic grower in Ontario, and the answer for Zone 6a is clear and consistent: grow hardneck garlic.
Hardneck garlic produces a rigid central stalk, the hardneck, and develops cloves arranged in a single ring around that central stalk. It is the variety type developed for and adapted to cold northern climates and performs reliably through Ontario's Zone 6a winters without any special protection beyond a good layer of mulch. Hardneck garlic also produces garlic scapes in June, the curling green shoots that emerge from the central stalk before harvest, which are one of the most delicious and sought-after seasonal vegetables in Ontario farmers markets and home gardens. Hardneck varieties tend to have more complex, nuanced flavour than softneck types and are the overwhelming choice of serious garlic growers and chefs.
Softneck garlic is the variety most commonly found in grocery stores. It has a soft, braided-friendly neck, a longer shelf life than a hardneck, and produces more cloves per bulb. However, it does not handle the cold of a Zone 6a Ontario winter as reliably as hardneck and is better suited to milder climates. Growing softneck in Ontario is possible, but hardneck is the clear choice for consistent results in our climate.
Best hardneck varieties for Zone 6a Ontario:
Music is one of the most popular and reliably performing hardneck varieties in Ontario, producing large, beautiful bulbs with four to six fat cloves and a rich, robust flavour with moderate heat. It is widely available at Ontario garden centres and seed suppliers and an excellent starting point for first-time growers.
Rocambole types like Spanish Roja produce extraordinarily complex and nuanced flavours that many garlic enthusiasts consider the finest of all garlic types. They have thinner skins than other hardneck varieties and a somewhat shorter shelf life, but the flavour is exceptional.
Porcelain types like Music and German White are among the most winter-hardy of all garlic varieties, making them particularly reliable in Zone 6a Ontario conditions. They produce fewer but very large cloves with a strong, full flavour.
Purple Stripe varieties like Chesnok Red produce beautiful purple-streaked wrappers and excellent flavour. They are among the best varieties for roasting and develop a wonderfully sweet, mellow flavour when cooked slowly.
When to Plant Garlic in Zone 6a Ontario
Timing is the detail that first-time garlic growers most often get wrong, either planting too early in warm soil that encourages too much top growth before winter, or planting too late in already-frozen ground that prevents root establishment before the coldest weather arrives.
The ideal planting window for garlic in Zone 6a Ontario is from late September through to the end of October, with mid-October being the sweet spot for most GTA locations. At this point soil temperatures have cooled sufficiently to prevent excessive top growth but remain warm enough above 10 degrees Celsius at planting depth for roots to establish before the ground freezes.
A simple rule of thumb: plant your garlic two to three weeks before you expect the ground to freeze solidly in your area. In Zone 6a Ontario, the ground typically freezes hard in late November to early December, making mid- to late October the most reliable planting window across most of the GTA.
Garlic planted in this window will produce just enough top growth, typically a few centimetres of green shoot emerging above the soil, before the ground freezes. This is normal and healthy. The young shoots are hardy enough to survive Zone 6a winters without any special protection beyond mulching.
What happens if you plant too early:
Warm September soil encourages aggressive top growth that becomes the focus of the plant's energy. This top-heavy growth going into winter can be killed back by hard frost, stressing the plant and reducing bulb quality the following summer.
What happens if you plant too late:
Cloves planted into already-frozen soil cannot establish roots before winter and may rot, shift out of position through freeze-thaw action, or fail to survive entirely. If you miss your window in October, wait until spring and accept that your harvest will be smaller than fall-planted garlic would produce.
How to Prepare Your Garlic Bed
Garlic is not a demanding crop but it does have one non-negotiable requirement: well-drained soil. Garlic bulbs sitting in waterlogged soil through an Ontario winter will rot. Full stop. If your garden has poorly draining clay soil, raise your garlic bed slightly or plant in a raised bed where drainage is reliable.
Beyond drainage, garlic responds well to fertile, well-amended soil that has been prepared with a generous amount of compost worked into the top 20 centimetres before planting. Garlic is a nine-month crop, and the fertility you put into the soil at planting time is what it draws on through its entire growing season.
Remove any weeds from the planting area completely before preparing the bed. Garlic does not compete well with weeds, and a weedy garlic bed produces noticeably smaller bulbs than a clean one.
If your soil is heavy clay, incorporate coarse sand or fine grit along with compost to improve drainage before planting. A raised bed filled with quality triple mix and compost is the most reliable solution for gardeners dealing with seriously compacted or poorly draining soil.
How to Plant Garlic Step by Step
Step 1: Source quality seed garlic.
Purchase garlic from a reputable garden centre or seed supplier rather than using grocery store garlic for planting. Grocery store garlic is often treated to inhibit sprouting and may carry diseases that can persist in your garden soil for years. Quality seed garlic is certified disease-free, suited to Canadian growing conditions, and clearly labelled by variety so you know exactly what you are planting.
Stop by Lakeside Garden Gallery in September and October when our seed garlic selection is at its widest. Our team can help you choose the right variety for your taste preferences and growing conditions.
Step 2: Separate cloves immediately before planting.
Break your garlic bulbs into individual cloves the same day you plant them rather than days in advance. Separating cloves exposes the base of each clove where roots will emerge, and this exposed surface can dry out and become less viable if left too long before planting. Choose the largest, firmest cloves for planting, and set aside any small or soft cloves for cooking rather than wasting prime garden space on cloves that will produce smaller bulbs.
Step 3: Plant at the correct depth and spacing.
Plant each clove with the pointed end facing upward and the flat base facing down, 5 to 7 centimetres deep measured from the top of the clove to the soil surface. Space cloves 15 centimetres apart within rows and leave 30 centimetres between rows to allow adequate room for bulb development and air circulation.
Deeper planting in Zone 6a provides better winter protection and reduces the risk of cloves being heaved out of position by freeze-thaw cycles. If your soil is light and well-draining, planting at the deeper end of the 5 to 7 centimetre range is always a safe choice in our climate.
Step 4: Mulch generously and immediately.
This step is non-negotiable for Zone 6a garlic and the one most commonly skipped by first-time growers. Apply a 10 to 15-centimetre layer of straw, shredded leaves, or other organic mulch over your garlic bed immediately after planting. This mulch layer insulates the soil, moderates temperature fluctuations through freeze-thaw cycles, retains moisture, and suppresses the weeds that will otherwise compete aggressively with your garlic the following spring.
The mulch layer in Zone 6a is not optional. It is the difference between a successful garlic harvest and a disappointing one in a cold Ontario winter.
What to Expect Through the Growing Season
October through November:
Cloves establish roots and may push a few centimetres of green shoot above the soil surface before the ground freezes. This early emergence is completely normal and healthy.
December through February:
Garlic goes dormant under the snow and mulch. No visible activity above ground. Nothing to do. This is the easy part.
March through April:
As soil temperatures rise, garlic shoots emerge through the mulch with remarkable vigour, often appearing before almost any other plant in the garden. Pull back or thin the mulch layer slightly to allow shoots to grow freely but leave enough to continue suppressing weeds.
May through June:
Garlic grows rapidly through spring, producing tall green shoots. In June, hardneck varieties produce garlic scapes, the curling green spiral shoots that emerge from the central stalk. Harvest scapes when they have made one full curl by cutting or snapping them off just above the top leaf. This redirects the plant's energy from scape development back into bulb formation and improves final bulb size. Garlic scapes are delicious sautéed with butter, blended into pesto, chopped into scrambled eggs, or used anywhere you would use garlic. They are one of the most exciting and fleeting seasonal treats in the home vegetable garden.
Late June through July:
Garlic is ready to harvest when the lower three to four leaves have turned brown and dried while the upper leaves are still green. This typically happens in late June to mid July in Zone 6a Ontario, depending on the variety and the specific season. Do not wait for all leaves to brown since the wrapper around the bulb will begin to deteriorate as the plant fully dries out.
Harvest by loosening the soil around each bulb with a garden fork rather than pulling by the stem, which can break off and reduce storage life. Cure harvested bulbs in a warm, dry, well-ventilated location out of direct sun for three to four weeks before trimming roots and stems for storage.
How Much Garlic Should You Plant
A single bulb of seed garlic typically contains four to eight cloves depending on variety. Each clove becomes one full bulb at harvest. So one bulb planted becomes four to eight bulbs harvested. A ten-bulb purchase produces forty to eighty bulbs, more than enough to supply a family with cooking garlic for the year with a surplus to set aside as next year's seed stock.
A commonly planted quantity for a family of four is 50 to 75 cloves, which requires a bed roughly 1 meter wide and 2 to 3 meters long. This is genuinely manageable even in a small Ontario backyard and produces a harvest that feels remarkably abundant for the modest space and effort invested.
Your Garlic Journey Starts This September
Growing your own garlic is one of those gardening experiences that changes how you think about food and about what is possible in a Zone 6a Ontario garden through the long winter months. The fact that something is quietly developing underground through the coldest stretch of the year and then emerges triumphantly in spring to produce one of the most flavorful and useful crops in the kitchen is genuinely extraordinary when you experience it for the first time.
Stop by Lakeside Garden Gallery this September and October and let our team help you choose the right seed garlic varieties, soil amendments, and mulch for your first, or your best, garlic harvest next summer. 🧄🌱