When to plant garlic in Ontario: a fall timeline

Short answer: mid-October to early November for most of Ontario. The rule underneath the dates is roughly two to four weeks before your ground freezes hard — long enough for roots to establish, short enough that the shoot doesn’t push through and get winter-burned.

Dates are a proxy. What garlic needs is a stretch of cool, workable soil in which to grow roots, followed by a winter. Read your own fall, not the calendar.

Regional windows

Region	Typical window
Northern Ontario	Late September – mid-October
Ottawa Valley / eastern Ontario	Early – late October
Central Ontario, Grey–Bruce, Dufferin	Mid-October – early November
Southwestern Ontario	Late October – mid-November
Niagara / Essex	Late October – late November

Two things shift these dates more than a map can. Soil type: clay that freezes wet is a bad place for a clove to spend the winter. Elevation: within one county, high ground freezes earlier than the valley below it. If you have grown garlic here before, your own records beat any table on the internet, including this one.

The timeline

Late summer: choose and order seed

Order seed garlic in August and September. Good stock sells out, and by October you are choosing from what is left.

Buy the largest bulbs you can afford. Clove size is the strongest predictor of next year’s bulb size, and cheap small seed is the most expensive decision on this page. Hardnecks — Music, Porcelain types, Rocambole — are what most of Ontario grows. If you save your own seed, save from your best bulbs, not from what didn’t sell.

Six to eight weeks before planting: soil prep

Garlic wants well-drained ground, a pH around 6.5, and plenty of organic matter. It does not want wet feet in March, which is the most common way an Ontario garlic crop is lost — not cold, water.

• Test your soil if you have not in three years. Garlic is a heavy feeder, and October is too late to find out you are short.
• Amend with compost or manure well before planting, not into the furrow on the day.
• Deal with drainage now. If a spot ponds after heavy rain, don’t plant garlic in it. Raised beds are the standard answer on heavy ground.
• Rotate. Don’t follow garlic, onions or leeks with garlic. Three to four years out of alliums is the usual advice, and white rot is why.

Planting week

Crack the bulbs close to planting — one to two days ahead, not two weeks. Breaking a bulb exposes the basal plate, and once exposed it dries out. A clove cracked in early October and planted in November has lost vigour you paid for. Keep the papery skin on, and discard anything soft, mouldy, damaged or tiny — tiny cloves grow tiny bulbs in full-price row space.

Spacing. Most Ontario growers land between 4″ and 8″ in-row, with rows 6″ to 8″ apart. Closer gives more bulbs of smaller average size; wider gives fewer, larger bulbs and easier weeding.

Spacing	Cloves per acre
4″ × 6″	261,360
6″ × 6″	174,240
6″ × 8″	130,680
8″ × 8″	98,010

(An acre is 6,272,640 square inches. Divide by your spacing — the full method is in cloves per acre.)

Depth. Two to three inches to the tip of the clove in most Ontario soils, three to four on light sand or where you are not mulching. Too shallow and the clove heaves out over winter; too deep and emergence is slow and uneven.

Orientation. Root plate down, pointed tip up, every clove. A clove planted sideways or inverted still grows — it grows a bent neck and a smaller, misshapen bulb, explained here.

Two to four weeks after planting: mulch

Mulch once the soil has cooled but before the ground freezes. Too early keeps the soil warm and encourages top growth you don’t want going into winter.

Four to six inches of clean straw is standard in Ontario. Its real job is moderating the freeze-thaw cycling that heaves cloves out of the ground in February and March — stability matters more than insulation — and it suppresses spring weeds. Use straw, not hay: hay carries seed.

Late fall: leave it alone

Green shoots before the snow are normal in a mild fall, not a disaster. The plant is fine. Do not pull the mulch off to look.

Spring

• Pull back mulch only if the ground stays wet. Most growers leave it and let the shoots come up through it.
• Feed early. Bulb size is set by the leaves made in spring, so nitrogen wants to be available in April and May, tapering off by early June.
• Weed relentlessly. Garlic competes badly, and weed pressure in May and June costs bulb size directly.
• Snap scapes on hardnecks when they curl, usually mid to late June. Leaving them on costs bulb size. They also sell.

July: harvest

Harvest when the bottom third to half of the leaves have browned and the upper leaves are still green — usually mid-July to early August. Dig one bulb and look: wrappers intact, cloves filling their skins. Too early and bulbs are small and undivided; too late and the wrappers split and it won’t store.

Lift, do not pull. Loosen the row first — a garden fork on a small planting, a blade under the bed on acreage — because a plant pulled from firm ground snaps at the neck. Why necks break covers that.

Curing

Cure three to four weeks in a shaded, dry space with air moving across the bulbs. Not in direct sun, which sunburns wrappers, and not in a closed shed — airflow is the whole job. It is cured when the neck is dry through and the wrappers are papery. Then trim, grade, and store cool and dry.

What this page is not

This is general agronomy. It is not a substitute for your own records, your regional grower association, or OMAFRA crop guidance. Varieties differ, soils differ, and the season you are actually in differs from the average one every year.

And a note on equipment, since this is an equipment company’s website. Nothing on this page requires a machine, and a machine will not change the calendar above. What it changes is planting week. On a PL-22 two riders sit instead of kneeling, a third person drives, and the rate holds through the afternoon; every clove goes in root-end down, with no double-drops or skips; and you are not depending on finding a big crew in the middle of October. The undercutter mounts to the same frame, so the machine that plants in October lifts the crop in July. That holds at one acre as much as at ten.

The comparison against hand-planting works through the labour arithmetic for one acre, and the cost calculator runs it at your own crew’s rate. Or call Doug on 519-379-6210 — we are in Dundalk, and we plant on the same calendar you do.