Guide

How many garlic cloves per pot, by pot size

At 4 inches between cloves, a 12-inch pot holds about 7 garlic cloves, a 16-inch pot 12 and a 20-inch pot 19. The pot needs at least 8 inches of soil. Plant in October or early November and leave it outdoors over winter, because garlic needs a cold spell before it will form a bulb.

By Moses Emmanuel

Garlic cloves per pot: the chart

Counts for round pots, measured across the top on the inside. Each column is one spacing between cloves. Utah State plants garlic 3 to 4 inches apart, Oregon State 4 inches, University of Maryland anywhere from 3 to 6, and Wisconsin about 6. Our square-foot planting chart puts garlic at 9 per square foot, which is the 4-inch column.

• 8 in
• 10 in
• 12 in
• 14 in
• 16 in
• 18 in
• 20 in
• 24 in

How we got the numbers: the area of the pot's surface divided by the square of the spacing, rounded down. That is the same arithmetic the square-foot method uses, and in a round pot it works because the cloves go in staggered rows. A 12-inch pot at 4 inches is the easy one to picture, with one clove in the middle and six in a ring around it.

Rectangular planters lose a little at the ends, so count them row by row: how many spacings fit across the width, times how many fit along the length.

Garlic pot calculator

Measure the inside of the container. For a round pot, enter the width across the top and leave the second box alone. The soil figure is the pot's volume to the depth you enter, so it reads a little high for pots that taper.

Wet potting mix is heavy. Before you line a railing with deep planters, run the soil volume through our balcony weight calculator.

Which spacing to pick

Four inches sits inside the range of three of the four extension services, so it is our default, and it matches the 9-per-square count. Wisconsin's 6 inches is the roomy option, and it costs you more than half the cloves: a 12-inch pot drops from 7 to 3. Three inches gets the most garlic into a small pot. Utah State pairs it with rows 6 to 10 inches apart, which a pot does not have, so every clove ends up 3 inches from all of its neighbors.

Whichever you choose, plant the largest cloves from the bulb. Utah State says to set them unpeeled with the pointed end up, and the small inner cloves can go into the kitchen. Wisconsin Extension counts four to 12 cloves on a hardneck bulb and 10 to 40 on a softneck, which is where the bulb estimate in the calculator comes from. Maryland describes softneck cloves as small, though they keep longer.

When to plant garlic in a pot

Late October falls inside most of the planting windows below. University of Maryland Extension plants in mid to late October so the cloves can put down roots and a few leaves before the cold arrives. Wisconsin waits until a week or two after the first killing frost. Oregon State plants from September to mid November in the Willamette Valley and the east of the state, and Utah State from late September through November.

A pot does not change the date. It does have to stay outdoors through winter, since a heated room would skip the chill that Maryland gives as the reason spring-planted garlic stays small: the cloves need about two months at 32 to 50°F before the bulb starts to swell, and the long days of early summer then set the swelling off.

Buy cloves from a nursery or garden center. Oregon State points out that supermarket garlic is often treated to keep it from sprouting, and suggests cured cloves from a nursery or from your own last crop.

Depth: the pot and the clove

Oregon State's minimum for a garlic container is 8 inches deep, with drainage holes near the bottom. Most of that is root room. The clove itself goes 2 to 3 inches down, pointed tip up, by Wisconsin's and Utah State's figures, while Maryland covers it with 1 to 2 inches of soil. In a pot we would go with 2 inches and leave space under the rim for mulch.

Our container size chart has the depth for other crops if the pot is going to be shared later in the year.

Winter on a balcony

Once the cloves are in, Wisconsin covers the bed with 3 to 4 inches of clean straw, pulls it back in spring after the risk of hard freezes is over, and puts it back when the shoots are about 6 inches tall. A pot gets the same treatment.

The worry in a pot is the roots. A UMass Extension fact sheet on container plants points out that roots are much less hardy than shoots, and that an unprotected pot loses the warmth a garden bed keeps around its roots. That research is on nursery perennials, and we found no study on garlic in pots, so treat this as our own advice: through a hard freeze, push the pots together against the wall of the building, out of the wind. The leaves themselves come through light frost well, as the frost tolerance chart shows.

Feeding, scapes and harvest

Wisconsin calls garlic a moderate to heavy feeder and gives it nitrogen at planting and again once the shoots are 4 to 6 inches tall. Oregon State feeds in early spring and again in May as the days lengthen, and Maryland's schedule is fall, April and, if needed, late May. Potting mix holds little in reserve, so the spring feeds matter more in a pot; how to dose them is in container fertilizer basics.

Hardneck garlic sends up a curled flower stalk called a scape. Wisconsin removes it just after it starts to curl. The difference it makes depends on feeding: leaving scapes on cut yield by up to 30% in poorly fertilized soil and by less than 5% where the soil was well fertilized. The scapes are good to eat, and Maryland uses them in place of scallions.

Lift the bulbs when about half the leaves have turned brown, which in Maryland is late June or early July and in Oregon June or July. Tip the pot out onto newspaper and pull the bulbs from the loose mix. To cure them, Oregon State spreads the plants in a warm, dry, shady place with good air for 2 to 3 weeks; Wisconsin allows 3 to 4 weeks. When the skins are papery, trim the roots and tops, and set aside the biggest bulbs for next October's pot.

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