Geoff McCabe

Growing Garlic in the Tropics

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Growing garlic in Costa Rica

Nov 12, 2012:

We are growing garlic on the farm, which is a humid, hot, tropical climate. I haven’t heard of anyone growing garlic in our part of Costa Rica, but since our uneaten garlic bulbs seem to like to sprout on their own, it seems like they should grow here. A little research on the internet said it wouldn’t work, but some more in depth searching turned up more information describing how to do it. It’s a good thing I’m not the type of person to give up easily or I would have declared this impossible.

The process is tricky, but simple. Garlic cloves apparently need cold weather during their infancy to grow properly into bigger bulbs later in life. If I had planted these directly into the soil, they may have grown into nice plants, but we would have been disappointed that the bulbs themselves didn’t form well into the type of garlic that we want to eat.

How to choose the right cloves to plant

We are using garlic purchased from the local supermarket in Cobano, which is from China, and not organic, because I don’t know of any other source here in Costa Rica. We select the bulbs that have the fewest, but larger cloves, because we’re only going to plant the fattest ones. The smaller cloves will be used for cooking.

Preparation before planting

We must trick the garlic cloves into thinking they’re experiencing some frost, so after selecting the largest cloves, we put them in a bag in the refrigerator, with the date market on it. After 4-6 weeks at temperature below 40°F (4°C) (but not too cold, so don’t use the freezer) we will pull them out for planting.

The cloves are then stripped of their drier outer layers, leaving only the inner-most skin as intact as possible.

Planting and growing garlic

The cloves are planted individually, pointy tip up, two inches below the ground. They should be around 3 inches (7cm) apart in their rows, with the rows 12-24 inches apart.

They must be in well-drained soil, rich in nutrients. Some people add sand to make sure the soil drains well. You will need a minimum of 6-7 inches (15cm) of soil underneath the bulb for the roots to grow and to assure drainage. We are growing garlic in bags, but raised beds are recommended as well, especially if your soil has a lot of clay.

Some garlic growing aficionados recommend reducing the amount of water that you put on the garlic with every month that passes during their life-cycle, which will make the garlic flavor better and stronger.

Harvesting Tips

Garlic grows slowly and the harvest will be several months later. The bulbs are generally ready when the leaves of the plant are starting to brown. Don’t wait too long. Pull out the plants out by their necks after letting the soil get dry but holding back on the water for a week or so before harvest. If they don’t seem to be coming out easily enough, use a pitchfork to loosen the soil and pry them up by getting the tines of the fork underneath them.

Garlic looks tough but is fragile at first, so be gentle with the bulbs so they aren’t bruised. Lay the bulbs (with the stems and leaves still attached) in a dry place and wait until all the leaves have fallen off. The garlic is ready when cutting the stem off doesn’t give you a strong garlic odor. Don’t store it in a sealed container. Left out, it should last several months, and long enough to get ready for your next harvest.

Garlic Sprouts – One of the world’s best kept food secrets

Have you ever heard of garlic sprouts? Seen them on a menu? Probably not. This is a rare delicacy that I discovered in China. Every year for a few weeks, garlic sprouts are available at restaurants in Southern China, and are one of the tastiest vegetables on earth. They look like asparagus, but have a wonderful, mild built-in garlic taste. We eat them stir-fried with garlic, salt and pepper, and oil. Of course, cutting off the sprouts will kill the plant before it can grow up and grow the clove into a bulb, but it’s a very exotic treat that I recommend trying with some of your garlic.

Additional Benefits of Garlic in the Garden

Many insects don’t like the smell of garlic, so it can be strategically planted in your garden or farm. We are experimenting with planting it at the ends of each raised bed, to somewhat encircle other plants growing inside.

Health Benefits of Garlic

Garlic is on nearly every nutritionist’s list as a top Superfood. Not only does it supposedly repel vampires, but it’s one of the best anti-bacterials known. Hence, we try to keep garlic out of our compost piles, because they inhibit the bacteria in the soil from doing its decomposing work.

Recent studies have shown that garlic stimulates red blood cells to produce hydrogen sulfide, which has been shown to prevent many forms of cancer and heart disease.

You’re going to need to eat a lot of garlic… at least two cloves per day. In many societies that have very low cancer and heart disease rates, the people eat even much more than this… 8-10 cloves per day! Luckily, garlic is super-tasty, so eating a lot of it isn’t so difficult.

Important tip! Your garlic eating can be more effective if you mince it 10-15 minutes before cooking it. The oxidation process produces enzymes that make the garlic healthier.

Afraid of having stinky garlic breath? Eating fennel seeds with your garlic is said to reduce the smell of it coming from various parts of your body.

Garlic used to treat parasites

A common remedy for parasites is to mix garlic with other herbs such as wormwood and black walnut, all of which produce a slight toxicity that the bugs in your body hate.

It can also be used as an anti-parasitic without eating it. In the old days, people would make collars out of garlic cloves and wear them, which drives away parasitic worms from inside your body. Eating garlic and wearing the collar have been proven to be very effective treatment, and was used for hundreds, or possibly thousands of years before modern medicine. I’m guessing that the garlic can enter the bloodstream directly, through the thin skin of one’s neck, and over time creates an environment throughout the body that’s repugnant, or perhaps toxic to worms. This “souring of the blood” probably is also likely to be what keeps vampires at bay.

Results of First Test

Garlic Sprouting in BagI wanted to comment that this did NOT work. I sprouted them in the fridge, which worked great, and then planted around January, which is the beginning of dry/hot season here.

They grew very well for a while but after the greens reached about 16 inches high, they stopped growing. I kept them during this time in our shade structure (80% shade) so perhaps that’s the reason. I believe we can get this to work but I still haven’t tried it again. Next time, once they start growing, I’d move them into the full sun.

I had first tried this with cloves from China that were from the local market, and later found Costa Rica-grown organic garlic, which was much smaller. I spent hours stripping them and put them in the refrigerator, and then our cleaning lady threw them away just as they were ready to plant!

So I need to do that again, but with 120 or so different edible plants we’re working on simultaneously, others are taking priority at the moment. I just noticed that a lot of people commented on this article so I’m going to make this a priority and will try to use both garlic sources. If anyone has tried this with better success, please comment or let me know!

Third Attempt

June 1, 2014: I’m trying this again (using Chinese garlic from the local store), and making some modification to how I’m doing it. The changes are:

1. Plant them directly in the soil, in raised beds, with lots of mulch on top, after growing them in a plastic bag in the refrigerator for 6-8 weeks. They sprout very well and grow both a top and the roots in the refrigerator. I tested them in the freezer too but this doesn’t work and just killed them.
2. The beds will have full sun.
3. It’s the beginning of rainy season so they’ll get a lot of water. So they must have very good drainage.
4. I’ll plant the bulbs one inch below the surface. In most cases the green tip that has already sprouted will be above the soil. However, the mulch will cover them and I expect they’ll grow through the mulch to find the sun.

If this doesn’t work, then next time I can try the following changes:

A. These have been peeled of their driest outer layers, and have sprouted well in the cold refrigerator. However, I’ve read online that this part isn’t necessary in temperate climates. So I can try them without peeling them.
B. Some websites recommend soaking the bulbs for “a few hours” in a solution of one gallon water plus 2 tablespoons baking soda and also some seaweed extract (we only have the first here). This is supposed to protect them from insects and I think I can do this before putting them in the refrigerator.
C. Try growing them underneath a clear plastic roof, where they get nearly full sun, but where I can control the water to just 1-2 inches per week rather than the random heavy inundations that the Costa Rica rainy season climate provides.

Fourth Attempt

Now finally I’ve been able to find some excellent information about growing garlic in Zone 13 (tropical climates). These important tips are as follows:

    1. The cooling/chilling process is called “Vernalization” and needs to be done for a minimum of 10-12 weeks before planting. Bulbs should be planted deep (6-8 inches) after vernalizing them, which helps them grow longer roots.
    2. They should be watered well, but not often, which encourages them to grow deeper roots.
    3. They can be protected from hot afternoon sun by good use of shade. I’m contemplating using some green garden “saran” mesh as a wall on the west side of the garlic growing beds, to block the afternoon sun.
    4. Deep, light colored mulch is also recommended.
    5. I found two varieties suitable for the tropics, as shown below (Creole and Artichoke).

Armed with this information, I will attempt this again and hopefully finally have some growing garlic bulbs within 6 months or so!

Types of Garlic Best for Tropical Climates

Artichoke: – Grey Duck Garlic recommends the Thermadrone variety (Buy Thermadrone Garlic)
Turban: – Thai Purple Turban garlic is recommended for hot climates.
Asian Tempest: – Asian Tempest is an “Asiatic” garlic clove that’s recommended for tropical climes.

Video on Vernalization

Garlic Suppliers with Hot Weather Varieties for Sale

Red Rosa Farm – Located in Indiana, and sells online at
Filaree Garlic Farm – Has four families of garlic available for September shipping: Artichoke, Asiatic, Creole, and Turban

Additional References

Southern Garlic Grower Guide – Grey Duck’s great explanation of how/when garlic bulbs grow, related to weather and other growing conditions.
Gourmet Garlic Gardens – Detailed information about every type of garlic, and where to buy it.
Garlic Health Science – Unlocking the Health Benefits of Garlic” in the New York Times.
Growing Garlic – Tips from