Cultivation Of Crops: How to Grow Garlic

How to Grow, Harvest and Market Garlic in Zimbabwe

Garlic takes its name from the words gar (spear) and leac (leak) because of its sharp, tapering leaves. We generally tend to think of garlic as only one type; the type that we see in the supermarket. Yet they are over 200 varieties of garlic.

So, why grow garlic?

Although it is a labor intensive crop, it is easy to grow and unlike most vegetables it stores well. It is great for commercial farmers as well as urban farmers. Garlic demand is also rising as more consumers appreciate its flavour and many health benefits.

Types of Garlic

Garlic is part of the allium family which includes onions, leeks and chives. If you are familiar with growing onions, you will notice that garlic has similar qualities to onions.

Garlic can be divided into two mains types: soft-necks and hard necks.

Soft-necks: These are easy to grow, braidable, long storing and have good flavour. Almost all the varieties you find in supermarkets are soft-necks. An example of a soft-neck is the California White variety.

Hard-necks: these are also known as seedstem garlic because the shoot up a "flower" stem (scape) that needs to be removed because scapes can reduce bulb growth and yield. Hard-necks are more fragile and flavourful than soft-necks. Some examples of hard-neck cultivars include Porcelain, Purple Stripe, Marbled Purple Stripe, Glazed Purple Stripe, Asiatic, Turban, and Creole varieties.

Garlic Varieties

So how to you pick which garlic variety to grow?

Pick a variety based on your specific region and your customer's preferred culinary needs. Your yield will vary based on your soil, climate zone, altitude, and garlic variety.

Best garlic varieties to grow: California late, California early (adapts well to a variety of climates and stores well), Spanish Roja, Inchelium Red, Elephant, Polish White, German Red and Silver Rose.

Where to buy: you can buy garlic bulbs (planting stock) from a reputable farm supplier or garden center. If you can't find any locally you should consider importing planting stock from South Africa. Just make sure you follow the correct importing procedures and also look at the reviews of your potential supplier.

Choose garlic bulbs that are large in size and disease free. Don't use the garlic you find in the supermarket unless you are just experimenting for fun. The variety of garlic planting stock you choose to grow is the single greatest factor in determining your garlic growing success.

When to Plant Garlic

Garlic grows well in temperatures of between 12-25 degrees C. Therefore the best time to plant your garlic is in late summer, between Mid-February to April. This is because it requires 40 days of vernalization (exposure to cold) for the cloves to sprout and develop bulbs. Note that garlic has a fairly long growing season of about 26-35 weeks from planting to harvest.

Sample Planting schedule:

Send your soil for testing: January
Begin soil preparation: January
Start planting: mid-February/March/ April
Irrigation: February to July
Fertilisation - at planting; 6-8 weeks later
Pest Control: February - September
Weed Control: February - July
Harvesting: August/ September/October
Marketing: August - December

Soil & Site Selection

Choose a sunny spot with good soil. Garlic does best in rich, well-drained soil, with a soil pH of 6.5 to 7 (neutral to slightly acidic). do a soil test months before you plan to grow your garlic. This will give you enough time to apply agriculture lime if you need to raise your soil pH.

To improve your soil structure, moisture retention and nutrient levels apply organic matter such as aged manure and compost.The better your soil, the better your garlic will grow.

Garlic does not do so well in clay soil. To grow garlic in heavy clay soil, you will need to dig in organic matter to improve the soil drainage.

Companion planting: garlic repels aphids so is great to plant with cabbage, lettuce, spinach, broccoli, kohlrabi, tomatoes, eggplant. Try to rotate your crops and avoid growing garlic where you previously grew plants in the allium family (such as onion, leeks and chives) in the past 3 years.

How to Plant Garlic

Bed Preparation:

Step 1

Remove any debris from previous crops. It is important to get rid of weeds. To remove weeds, you can irrigate the fields to germinate weed seedlings, and then cultivate to remove them.

Step 2

Dig/cultivate your fields, then fertilise your soil with aged manure and compost to amend your soil structure

Step 3

Do a soil test and follow recommendations. If required lightly lime your soil to improve soil pH.

Step 4

Prepare raised beds, the recommendations on bed length vary. Level out the surface to prepare beds for irrigation.

Planting your garlic bulbs. Store your planting material as whole bulbs until you are ready to plant. When you are ready to plant, separate your cloves into individual cloves. Only do this just before you plant to avoid to avoid deterioration.

For a robust garlic crop, use the largest outer cloves for planting and discard or use the smaller inner cloves for cooking. Each planted clove will yield one bulb.

Plant individual cloves with the pointy end facing up, and root end (flat basal plate) at the bottom of the small hole. Cover with soil and mulch. Press down firmly as you cover the bulbs with soil and mulch. Shoots should appear within a month or so of planting.

Spacing: take the size of your bulbs into account when determining bulb spacing. Plant 2.5-4 cm deep and 10-15 cm apart with 30cm between rows. Just be sure not to plant the cloves too deep or they won't grow. The tip of the clove should be about 1cm below the surface. You can hand or machine plant your seeds depending on your available equipment. Expect a plant population of about 40 cloves/ m2.

Weeding, Watering and Fertilising Garlic

Mulching & Weeding:

Garlic is susceptible to water stress because of its shallow roots. Mulch your garlic plants using about 5cm of straw mulch to keep soil moisture especially in drier periods and areas. You can use other mulch beside straw mulch. Other mulch options include wood chips, hay, grass clippings, leaves and black plastic. You will mulch again later in the growing season.

Mulching also helps keep your plants weed free. This is important because garlic does not (like) compete well with weeds due to its shallow root system. If you allow weeds to grow in your garlic field you can suffer severe yield loss or reduced bulb size.

A good way to control weeds is by hand weeding garlic beds regularly during the growing season. While this can be labour intensive it is important. If weeds are truly uncontrollable you can look into certified herbicides.

Watering Garlic Plants

Garlic requires regular even watering to develop full-size bulbs and avoid moisture stress. Mulch helps retain water moisture. You should have set up your drip irrigation system or preferred watering system (water tank) at the land preparation stage to make sure your plants are well watered.

Water your plants in the morning or early afternoon to allow the water that falls on leaves to dry up before nightfall. For most soil types, plan to water regularly for a good crop. Plants need about 2.5cm of water per week during the bulb formation stage. Be careful to keep your soil moist but not wet. You can use a soil sensor tool to measure your soil's moisture and help with irrigation scheduling.

Stop or limit watering (to once or twice) when garlic is mature (starts to dry off). This is because the soil can remain wet and damage the plants just before you harvest.

How to Fertilise Garlic

Before you start planting you should do a soil test to measure your soil pH, nitrogen (N), phosphorus (P), and potassium (K). What fertiliser you use depends largely on how fertile your soil was to start with. Request a fertiliser program from your agro-dealer based on your soil test.

You will need moderate fertiliser if you amended your soil at soil preparation time and mulched your fields. In addition to basal fertiliser at planting, you will need extra side dressing of nitrogen (calcium or ammonium nitrate) at about 6 to 8 weeks after planting for good growth.

For organic farming, you can use manure and organic fertiliser instead of chemical fertilisers, but it must be analyzed to determine if it has all the nutrients your plants needs.

Garlic Pests and Disease

Garlic can be susceptible to a number of pests and diseases. Some of the diseases that afflict garlic are onion thrips and various fungal diseases like rust and white onion rot.

Controls. Prevention is better than spending a lot of money on pesticides. Here are some preventative measures you can apply:

Buy disease-free planting stock
Practice crop rotation
Remove any diseased plants from fields
Do not work wet soil
Apply mulches to prevent weed growth
Sanitize all growing equipment
Avoid excess water near harvest time
Cure plants before storing

Harvesting Garlic

Garlic is ready to harvest when most of the leaves are a yellow-brown colour and wither and fall back down. You can take out one or a few of your plants to see if they are ready for harvest. Test one or two bulbs for harvest readiness to avoid lifting bulbs too early. Lifting bulbs too early gives away size. If you lift them too late, the outer wrapper may tear or they discolour, open up or rot.

For a small scale planting, you can hand harvest. Use a garden shovel to help loosen the soil and lift off the entire plant. Shake off dirt from roots. Be careful not to damage plants.

Post Harvest

After harvesting cure your garlic. Curing is a process of drying garlic bulbs to increase their storage life. Place your garlic plants out of the sun into a dry, shady and well-ventilated area like a shed or garage. Once cured trim or remove garlic tops and roots and place garlic bulbs on open trays or open-mesh bags in a well-ventilated building.

Unlike most vegetables, garlic stores well for an extended period of time once it is well cured. If kept well and dry garlic can be stored for up to 5 months depending on your strain of the garlic.

Marketing Garlic

Garlic is graded by size, with larger bulbs getting a higher price. Pack your garlic in mesh bags, standard onion bags or in well-ventilated crates.

Before you transport your garlic make sure that is well dried.

A great tool for tracking garlic market prices is eMkambo. According to eMkambo, the price of garlic in December was $3/kg. The market price for garlic like most vegetables fluctuates based on supply and demand including from imports from South Africa.

Before you start growing your garlic, you should do some market research. A good place to start is to talk to supermarket produce buyers. Also, ask other farmers which supermarkets have a good record of paying farmers on time. Late payment can affect your farm profitability.

Other options are to sell to restaurants, processors (for spices, oils, soup) and pharmaceutical companies (for supplements). You will find that some large companies work on contract farming basis. You can also sell directly to consumers through fresh produce markets, classifieds ads and on social media (Facebook and Whatsapp).

Budget: For an acre of garlic you need to consider all the following to make sure you are in fact making a profit: soil test, lime, plowing, labor for land preparation, planting and harvesting, planting bulbs, mulch, fertilizer, herbicides, irrigation, transportation, operating and marketing costs.

Further Reading

Growing Great Garlic: The Definitive Guide for Organic Gardeners and Small Farmers by Ron L. Engeland (1995) Paperback

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{image source: a.sirkin}