How to grow garlic in containers (and 3 mistakes to avoid)

Growing garlic in pots and containers takes patience and preparation. But it is not difficult and it does offer wonderful possibilities for your kitchen garden.

Garlic is one of those vegetables that need a long time to develop. But you can use this to your advantage. Because when you are putting your vegetable garden to bed you should think about planting garlic for next year.

And you do not have to worry about being too late. As long as you get those garlic cloves planted before the ground freezes you are in good shape.

Read on to learn how you too can join the garlic-growing community and add another homegrown vegetable to your kitchen garden.

Just the facts: 
1. Use seed garlic to reduce risk of importing diseases
2. Use soil that drains well 
3. Plant garlic cloves late fall before first frost 
4. Protect bed with thick layer of mulch
5. Add slow release fertilizer come spring time 
6. Harvest as early as June or wait for garlic greens to wilt for fuller cloves 

On a side note, I almost renamed this article to "Why do I still get surprised when it snows late March" (video, opens in new window).

Update: Follow progress via photos taken at key moments (published at the end of this article). Use Quick Navigation below or click Watch us grow garlic over time with photos

Garlic needs time to grow and develop

Growing garlic takes a long time. And this is why it is ideal to plant garlic as not only the growing season but also the year comes to an end.

Garlic takes 7-9 months to develop and most of the time it only asks for a bit of water every now and then.

Plant your garlic cloves in November or December before the first frost for a harvest late next summer. You can of course harvest earlier but you will most likely find that the bulbs are not fully formed. It is generally better to wait for the leaves to go yellow before harvesting.

Choose the right type of garlic for your climate

It may be tempting to use garlic bulbs bought at your local grocery store.

But when you use grocery store garlic you do not know if the garlic you are planting suits your climate. Also, there is always a risk that store-bought garlic spreads diseases to your garden.

Worried about garlic breath? Read this article about how basic ingredients like apple, lettuce and mint leaves can help deodorize so called garlic breath. 

I recommend buying your garlic bulbs from a garden store. 

And it is not only due to the already stated facts. The main reason is actually that a small investment today will yield a harvest for consumption as well as garlic to plant next year.

You just need to get started the right way and then use part of your harvest for planting next year. Slowly but surely you will have all the plants you need for planting and consumption. 

And this is why I recommend starting with good-quality seed garlic from a reputable dealer.

This year we are growing 4 different varieties of garlic

Growing 4 varieties of garlic in containers
One bulb completed with 3 more to go
  1. Garlic Messidor – Softneck variety with good and constant yield
  2. Garlic Unikat – cold resistant, 8-13 slightly purple cloves per bulb, full of flavor, stores well
  3. Garlic Dukat – larger, oil-rich cloves with a strong flavor, 5-7 cloves per bulb. Stores well
  4. Garlic Thermidrome – used in French cuisine, very cold resistant, has a slight purple shade, and produces 8-14 cloves per bulb. Stores well.

Hardneck and Softneck garlic

When you look to purchase garlic for planting you will come across the terms Hardneck and Softneck garlic.

Hardneck garlic is best suited for cold climates and needs several weeks of cold weather to grow or “get started”. You need the temperature to stay around 4-10 degrees Celsius (40-50 degrees Fahrenheit) for several weeks for the Hardneck varieties of garlic to grow and develop bulbs. 

Softneck garlic on the other hand is better suited for growing in a milder climate. 

Here in zone 7, we are able to grow both softneck and hardneck varieties. The hardneck garlic variety produces fewer cloves but has a more complex and intense flavor. Hardneck garlic is for example the go-to favorite when we make pesto from our Thai basil plants. 

Softneck varieties are milder and sometimes more useful when you only want a hint of garlic in your cooking. An example would be a tomato sauce where I would look for bulbs with a depth of flavor rather than a taste of garlic.

If you live in a mild climate and still want to grow hardneck garlic you can give the garlic the cold temperatures it needs by placing the bulbs in a paper bag in your fridge for 10-12 weeks before planting.

But as a general rule, get the type of garlic that suits your climate. And softneck varieties are easier to grow in milder climates.

Use the right type of container for your garlic

Choosing the right type of container for growing garlic has to do with size and material.

I like to use a container that is at least 15 cm (6 inches) deep. And needless to say, the wider the container the more you can plant.

Good drainage is key and both pots and containers need drainage holes to help keep the soil moist but not wet.

The type of material depends on the climate and where you will place your containers. If you are planning to place the container outdoors in a cold climate you are better off using a container made from a frost-safe material. 

Today there are so many new materials that are affordable and durable. Or simply build and use a raised garden bed or wooden container like I do.

Sure, wood and water are not best friends. But I like to use organic materials and I can use my wooden container for years. And my drainage hole is created by not sealing the bottom of the container shut.

Material is of course less of a problem if you live in a milder climate or place your container in a shielded location like an outdoor greenhouse. 

Many new gardeners like to use terra cotta pots for everything. And it is a beautiful material with great properties. But terra cotta is not well suited for freezing winter climates and the material is known to crack.

A tip is to line your wooden container with newspaper before you add your soil to extend its lifespan.

Regardless of the type of container, you choose you should remember that garlic likes to grow in full sun. If you are using a container that can be moved easily this is of course not an issue. 

But if you grow garlic in raised garden beds like we do you should choose a garden bed in a full-sun location if possible.

Choosing a well-draining soil for garlic

It is important to use soil with the correct properties when growing garlic in containers.

You need to ensure that you use soil that drains well. This is one of the most important things to get right.

If your soil is too compact or dense your planted garlic cloves will sit in soaking wet soil and they will rot. This is especially important in areas with a lot of precipitation – yes, this includes melting snow.

I use my standard soil recipe as a base to make sure that the garlic will have a well-drained and fertile growing environment. I use LECA, vermiculite, compost, and perlite to get the structure I am looking for.

If you want to make it easy for yourself, buy a well-draining potting soil mix or vegetable garden soil with about 20-25% compost.

To fertilize or not

I do not add any fertilizer when planting my garlic cloves. I simply make sure that the soil I use is compost rich and fertile to sustain the cloves developing healthy root systems over winter.

But you can of course mix in a slow-release fertilizer when you plant your cloves. But remember that you do not want the cloves to sprout this side of winter. Frost is coming and you want growth to be happening underground.

Come early spring I add a slow-release fertilizer. My go-to fertilizer has an NPK of 4-1-2.

  • Nitrogen (4) will help the plant develop and grow strong.
  • Phosphorus  (1) helps the root system to grow strong
  • Potassium (2) helps the overall health and well-being of the plant

Before adding the fertilizer I use my hands to gently loosen the mulch that by now has formed a hard crust on top of the soil. 

Loosening the mulch will make it easier for the sprouts to come through and also helps aerate the grow bed.

How and when to plant garlic in pots and containers

When you have chosen your soil and container it is time to plant the garlic cloves. Plant your bulbs before the first frost. For me, in zone 7 this usually means mid to late November.

Break the bulb apart and separate the big cloves from the smaller ones. If you have the room you can plant all the cloves. But if you have to choose, always plant the bigger, healthier-looking cloves. 

Use your hands to gently separate the cloves from the garlic bulb
Take your time. Be firm but gentle not to break the cloves.

Be firm but gentle when you break the bulbs open. Gently remove the outer layers of skin but leave the skin covering the actual clove. 

Look for a weak spot and work from there. And do not rush it. Take your time. Some bulbs can be really difficult to break open.

When the cloves are separated from the bulbs, place them on top of the soil in your container.

Spacing garlic cloves and rows of garlic before planting
Place cloves on the soil to get the correct distance between plants and rows

Space the garlic cloves roughly 15 cm (6 inches) apart and leave 20 cm (8 inches) between rows. 

When you are pleased with how it looks you simply push the cloves about 7 cm (3 inches) deep with the pointy side up. Your soil should be loose enough for you to plant the cloves with ease.

When the cloves are planted, water them thoroughly and cover them with a thick layer of mulch. You can use straw, leaves, or pine needles for mulch and you want to add a thick layer (15 cm / 6 inches). 

When you have placed the mulch on top of the soil, water it again. You want the mulch to be wet but not soaking.

Garlic planted and container mulched and watered
Garlic cloves planted, mulched, and watered for winter.
And no, pine needles will not make your soil acidic. By the time the pine needles are broken down and incorporated into the soil they are pH neutral. I use pine needles as mulch successfully and here is a source that explains how it works. 

Remember to water your garlic

It is not exactly hard work to grow garlic in pots and containers. When the cloves are planted you only have to make sure that the soil does not dry out. For me here in zone 7, this is rarely a problem as precipitation and shifts in temperature help keep the bed moist. 

Still, do check every now and then as garlic does not like to dry out.

This is also one of the reasons why I prefer containers to pots. Larger containers (or larger pots) mean more soil and less watering as the bed retains water for longer.

Use normal watering practices and check for example once a week. When you do water you should water thoroughly. Do not water a little bit every day or so. And remember, if your container is placed outdoors you may not need to water for weeks as precipitation and melting snow may keep your soil moist.

Protecting containers against the cold

You should protect your container against the cold if you live in an area where you know you will have freezing temperatures for extended periods of time.

There are 3 easy maneuvers that will help insulate your container against the cold.

1. Raise the container off the ground

Simply place a couple of pieces of wood underneath your container to lift it off the ground. Creating an empty space of air will insulate your container from the cold ground.

2. Place a layer of leaves around your container

Gather leaves, pine needles, small branches, straw, etc, and pile them up against your container. Again this layer of organic material will create an insulating layer of air to help protect the container against the cold.

3. Cover the container in bubble wrap  

You can also wrap your container in bubble wrap. The air pockets serve as insulation against the cold.

There are of course commercial alternatives to bubble wrap including products like Styrofoam covers.

We only use what we have at hand including old blankets, cardboard, newspaper, mulch, etc. as it is free and works quite well for us in our zone.

Caring for the garlic plant come spring

As Spring arrives and the temperature starts heating up you should place your container in a sunny location that receives at least six hours of sun.

And it never ceases to amaze me how the garlic bulbs will sprout and grow under the mulch even when we have frost at night.

The photo below shows garlic sprouting and was taken on 27 February. This garlic is from the actual batch of garlic that was planted on 21 November last year when this article was first started.

Garlic sprouts after 3 months
Green sprouts are small but visible when mulch is removed (27 Feb).

And yes, we are still seeing frost at night and early morning. Day high temperatures are in the range of 5-6 degrees Celsius (low 40s Fahrenheit).

As the sprouts grow, the temperatures rise and the soil softens it becomes time to add a slow-release fertilizer. Read the instructions on your fertilizer and add it in proportion to the size of your container. You want a slow-release fertilizer for bulb plants. 

We use a slow-release fertilizer with an NPK of 4-1-2.

Nitrogen (4) helps the plant develop, Phosphorus  (1) aids the root system, and Potassium (2) helps the overall health and well-being of the plant.

I use my hands to gently loosen the mulch before I add the fertilizer. 

By now the mulch has formed a hard crust on top of the soil and loosening the mulch will also help the spouts breakthrough in their quest for sunlight.

The hardneck garlic varieties grow long thin green stalks called scapes from the bulb. You can choose to remove the scapes or leave them as evidence suggests that it has no impact on the size of your harvest. But as the scapes are edible I choose to harvest them for consumption.

Pests and diseases

Garlic gives off a robust aroma and taste and is widely used as an effective companion plant in the garden.

Still, garlic is by no means resistant to all types of pests and diseases.

The most common pests and diseases include Basal Rot, White Rot, Downy Mildew, and Nematodes [1].

Most of the diseases are soil-borne so it is important to use a quality garden or potting soil that drains well and to use yearly rotation in your planting schedule.

Also, to avoid importing diseases, do not plant any old garlic bulbs you have at home. Use a seed garlic bulb from your local garden center. It only takes one bad clove to spread a disease that could destroy your entire harvest.

Time to harvest your container-growing garlic

When the leaves turn yellow or brown it is time to harvest your garlic. For us, this usually happens in late July / early August.

You should harvest your bulbs within 1-2 weeks of the leaves starting to brown. If you wait longer the shell or papery cover will start to deteriorate and the bulb will fall apart.

The garlic bulb to the left was harvested too late and the protective papering has deteriorated
The garlic bulb to the left was harvested too late and the protective papering has deteriorated

If you are unsure, harvest one or two bulbs and check.

You can of course harvest your garlic earlier. You do not have to wait for mature bulbs to form. When the bulb is not yet fully formed the taste is often milder and you can of course also harvest the garlic greens. 

To harvest your garlic you can either use a spade to loosen the soil or simply empty the whole container on the ground.

Either way, you should use your hands to find the garlic bulbs. Let your harvested bulbs dry outdoors in a protected area with good air circulation.

Harvesting garlic is in many ways similar to harvesting horseradish where we empty the container and use our hands to sift through the soil for our treasured harvest.

3 mistakes growing garlic in pots and containers

When planting garlic outdoors in containers, there are 3 important points that are almost a bit counterintuitive.

Here are 3 mistakes you should avoid for a richer harvest.

1. Do not plant too early

Planting in early fall may seem like a good idea as the garlic plant will have more time to develop. But there is also a risk of planting too early.

You do not want your garlic cloves to sprout too soon. Frost and freezing temperatures are coming. You want growth underground and the garlic plant to develop a strong root system over winter.

As a rule of thumb, plant a week or so before the first frost and when it feels almost too late it is usually the right time to plant.

2. Using the wrong soil for garlic bulbs to develop

You need well-drained and compost-rich soil to grow garlic. 

If you are unsure grab a handful of soil and form a ball using your hands. You should be able to form a ball and place it on your palm. But it is equally important that the ball crumbles when you press it lightly with your fingers.

If your soil is too dense you can use LECA or perlite to loosen the coil structure. Or use compost and vermiculite to get soil structure and levels of moisture right.

3. Planting garlic cloves too shallowly & not using mulch

Planting the cloves 7 cm (3 inches) deep means that you also need to use a thick layer of mulch.

Yes, if you do not add mulch you could simply plant the cloves deeper.  How deep you ask? Depends on your climate. So keep it simple and use a mulch to protect against frost and freezing temperatures.

My recommendation is to always use a layer of mulch. After all, you should always cover your garden beds with mulch over the winter period – whether you are growing garlic in containers or not.

Watch us grow garlic over time with photos

21 November: Place garlic cloves on the garden bed to ensure proper spacing before planting. Use plant markers to indicate the variety of garlic planted (here Messidor, Unikat, Dukat, Thermidrome)

21 November: Mulch to shield the garden bed from the elements.

27 February: Green garlic sprouts poking through the thick layer of mulch.

27 February: Removing mulch for a closer look at sprouting green.

19 March: The cold hardy garlic sprouts coping with another frosty night and morning.

31 March: Still get surprised when it snows in late March.

22 April: Garlic greens thriving as the weather turns warmer.

22 April: Same as above, but the photo was taken closer up. Greens growing well.

12 June: Daisy finds a good place to hide as garlic greens continue to grow strong.

29 June: Test harvesting a Thermidrome garlic plant early to check on growth and bulb development.

June-August: Time to harvest the garlic bulbs.

June-August: Some of the harvested Messidor garlic bulbs (August 20).

Helpful sources:

[1] http://plantclinic.cornell.edu/factsheets/garlicdiseases.pdf

Meet the author: Mattias is an experienced gardener spending most of his free time on his knees among herbs, plants, and garden vegetables. For the past two years, he has been sharing gardening projects and how-to tutorials on the NordicLavender website and YouTube channel.