Most people learn how deep to plant garlic once, years ago, from somebody in a different climate. Two inches, four inches apart, pointy end up, done.
That advice is not wrong. It is just not finished, because how deep to plant garlic in Kitsilano is not how deep to plant it in Winnipeg.
How deep to plant garlic in Canada
When you work out how deep to plant garlic, measure from the top of the clove, not the base. In mild zones 7 to 9, plant 2 to 3 inches deep, or 5 to 8 cm; in colder zones 2 to 6, go deeper, 3 to 4 inches or 8 to 10 cm, so the clove sits below the worst of the freeze and thaw. Either way, space the cloves 4 to 6 inches apart, or 10 to 15 cm.
I am Darrell, and I have been planting on the wet coast for over twenty five years. How deep to plant garlic is the part people either fuss over or ignore completely, and the truth sits in between. It matters, and it is easy.
Why depth changes with your zone
Get how deep to plant garlic wrong on the shallow side in cold country and the clove gets pushed around. Ground freezes, expands, thaws, contracts, and over a few cycles it lifts things out of the soil. You come out in March and find cloves half on the surface with roots waving in the air.
Deeper planting puts the clove into ground that stays more even in temperature. It is not about protecting the clove from cold, because hardneck garlic wants the cold. It is about protecting it from movement.
On the coast the risk runs the other way. Our ground rarely freezes solid, but it stays wet from November through March. A clove buried too deep in heavy, saturated soil sits in water with no air around it, and that is how cloves rot before they ever root properly. Around Vancouver I answer how deep to plant garlic at the shallow end of the range and put more effort into drainage.
Here is how deep to plant garlic by region, in practical terms.
- Zones 2 to 4, prairie and northern gardens: 3 to 4 inches, 8 to 10 cm, with a thick mulch on top.
- Zones 5 to 6, most of Ontario, Quebec and the interior: 3 inches, about 8 cm.
- Zones 7 to 9, coastal British Columbia and mild pockets: 2 to 3 inches, 5 to 8 cm, on ground that drains.
How far apart should garlic cloves be planted?
Give each clove 4 to 6 inches, or 10 to 15 cm, in every direction. Closer than that and the heads compete and come up small. Wider is fine. If you are planting in rows, leave about 12 inches, or 30 cm, between rows so you can weed without standing on the bed.
Garlic has thin, shallow roots and it does not fight for space well. It loses to weeds quietly, so the single most useful thing you can do before planting is clear the bed properly rather than tidy it. That includes the roots of anything perennial.
Which end of the garlic clove goes up?
Flat base down, pointed tip up. One end of the clove is a rough plate where the roots came out of the parent bulb, and that end goes to the bottom of the hole. Planted upside down, garlic usually rights itself, but it wastes energy and often makes a smaller head.
In a bed of a hundred cloves, a handful planted the wrong way up matters far less than how deep to plant garlic in the first place. It is just an avoidable tax, and it costs nothing to look at each clove before it goes in.
Set the clove into the hole rather than pushing it down, especially in clay. Pushing compacts the soil right under the base plate, which is exactly where the roots need to go.
Depth in containers and raised beds
Containers change the maths on how deep to plant garlic. A pot loses heat from all sides, so the soil in it swings far more than ground soil does. Plant at the deeper end of your zone range, use a pot at least 20 to 25 cm deep, and put it somewhere sheltered from wind.
Raised beds shift how deep to plant garlic a little, because they warm up and dry out faster than ground beds, which is good on the coast and mixed news on the prairies. The soil in a raised bed also freezes harder because cold gets at it from the sides. If you are in a cold zone with raised beds, mulch heavily. We go through the whole autumn routine in preparing raised beds for winter.
If you are working entirely in pots on a balcony, we have a separate walkthrough on growing garlic in containers that covers watering and feeding through the winter.
Mulch, and how much
With how deep to plant garlic settled and the cloves in, water once until the bed is properly wet, then cover it.
In zones 5 and colder, lay 4 to 6 inches of straw or shredded dry leaves over the bed, roughly 10 to 15 cm. It looks like too much. By April it will have settled to almost nothing. That layer is what stops the freeze and thaw from heaving your cloves out over winter.
In mild coastal zones, 2 to 3 inches is plenty, about 5 to 8 cm. Too much mulch on already damp ground keeps the surface soggy and gives slugs somewhere pleasant to live. Pull it back a little in early spring once shoots are pushing through.
The other half of the decision
Knowing how deep to plant garlic sets the plant up. What actually sets the size of the head is which clove you put in the hole, and that is a bigger lever than most people expect. I have written it up separately in whether clove size matters when planting garlic.
The type you plant matters too. Everything above assumes hardneck garlic, which is what suits most of the country. If you are still deciding, here is the difference between hardneck and softneck.
For a bed this size you want stock that was grown for planting, not for eating. The hardneck varieties we chose for cold ground come as nine seed bulbs, which at this spacing fills a small bed or a long planter.
When to do it
You are reading the soil, not the calendar. The window opens when the ground has cooled off properly and closes when it locks up solid. For most of Canada that lands somewhere between late September and the end of October, later on the coast, earlier in the north.
If a trowel still goes in without a fight, you can still plant.
What you get out of it
Next July you will be lifting heads with a fork, brushing the soil off, and hanging them in the garage to dry while the kitchen smells of them. In June, before that, you will be cutting curled scapes off the hardnecks for supper.
Seed garlic reaches us in small lots and there is no reordering a variety once it is spoken for, because the growers harvest once a year and that is that. Booking now settles your packs on better terms than waiting for whatever is left on the shelf, and it puts the boxes in your hands while the ground is still workable.
Have a look at the seed garlic we are holding for this planting window.
If you would rather watch than read, Darrell covers soil, drainage and which way up the clove goes in a short video on our channel.
Why how deep to plant garlic is worth ten minutes of your time
Getting how deep to plant garlic wrong costs you twice. Once in October, when you buy good stock and bury it at a depth that suits a climate nothing like yours. Then again in July, when you lift heads half the size they should be and go back to buying garlic for the rest of the year.
The second cost is quieter. Look it up and fall planting advice for Canada comes back in ten versions that contradict each other, most written for somewhere with a different winter. You stand there with a trowel and no way to tell which one is wrong. Guessing is tiring in a way that digging is not.
Garlic is a sociable crop too. It goes over the fence, into jars at Christmas, home with your kids in a paper bag. When the heads come up heavy you feel a bit proud of the bed. When they come up small you say nothing and buy a bag at the shop.
What we can do is take the guessing out of the parts we control. Boxes of seed garlic are opened here on arrival, not at your door, and each bulb is pressed at the shoulders before it goes in a pack. Reserving ahead of the shelf holds better terms than waiting for the last stock. Darrell has more than 25 years of hands on gardening and landscaping behind him, and on this coast he plants at the shallow end of the range and puts the effort into drainage instead.
Settle how deep to plant garlic for your own ground and next July is a fork, a wheelbarrow and a garage that smells of garlic for a week. Leave it to chance and one October afternoon can quietly cost you the season.
Frequently asked questions
What happens if I plant garlic too shallow?
In cold zones the clove gets heaved out of the ground by repeated freezing and thawing, and you find it sitting on the surface in early spring with exposed roots. If you catch it, push it back in and re cover with mulch. On the coast, shallow planting is less of a problem and can help in heavy, wet soil.
Can I plant garlic too deep?
Yes, particularly in heavy clay or ground that holds water. A clove buried much beyond 4 inches has to spend stored energy pushing a shoot up through cold soil, and it sits longer in wet conditions on the way. In dense soil, err shallower and add mulch rather than digging deeper.
Do I need to water garlic after planting in the fall?
Water once, thoroughly, so the soil settles around the cloves and roots can start moving. After that autumn rain usually handles it across most of the country. Only water again if you are somewhere dry with no rain for a few weeks. Garlic sitting in saturated soil all winter is the bigger risk.
Should I fertilize the bed at planting time?
Work compost or a balanced organic fertilizer into the bed before you plant, because garlic sits in the same ground for nine months and roots into what is already there. The bigger feed goes on in early spring when leaves start growing, since that is when the plant is building the head.
Come and see us
If you garden anywhere around Kitsilano or the Vancouver Westside, bring a photo of your bed and we will talk through the depth for your particular soil. Clay behaves differently from a sandy Point Grey garden, and it is worth five minutes.
DH Garden Centre
3742 West 10th Avenue, Vancouver, BC V6R 2G4
Open daily, 11:00 to 18:30
604-929-7335
Keep reading
Have a plant question? Bring it to the counter.
DH Garden Centre is at 3742 West 10th Avenue in Kitsilano, Vancouver, open 11:00 to 6:30 every day. Bring the plant, or a photo of the spot you want to fill, and we will look at it with you. If you buy a pot here we repot the plant at the counter, soil included up to 5 litres.
