Garlic

Garlic is a kitchen staple. It requires patience but is easy to grow in a sunny spot with well-draining soil, and there are plenty of varieties to try. Growing your own garlic guarantees that what you eat is chemical free with zero food miles attached.

How to Grow Garlic Bulbs

Family: Amaryllidaceae
Binomial name: Allium sativum
Life Cycle: Perennial (usually grown as an annual)

Garlic varieties can be classified as hardneck or softneck. Hardneck varieties produce scapes (flower stalks), can be strong flavoured, and are better suited to cool climates. Softneck varieties do not produce scapes, are generally milder in flavour than hardneck varieties and are better suited to warm climates.

When to Sow Garlic

Garlic is a cool season crop. Use the table below to identify the best time of year to sow garlic in your climate.

	JAN	FEB	MAR	APR	MAY	JUN	JUL	AUG	SEP	OCT	NOV	DEC
Cool
Temperate
Sub-Tropical
Tropical
Arid

Preparation

Garlic plants are best grown in full sun. Choose a location that will receive at least 6 hours of full sun each day.

Garlic plants need a loose, well drained soil enriched with organic matter. Prepare soil by weeding it thoroughly, digging it over to at least a spade’s depth to loosen the soil, and adding aged animal manure or compost. Organic matter can be dug into heavy soil to lighten it so roots can grow freely. Keep the area free of weeds until planting. If there's any doubt about drainage, mound the soil into rows to plant into, or plant in raised beds.

How to Plant Garlic

Garlic cloves grow best when planted directly into the garden.

Separate bulbs into individual cloves. Do not plant very small cloves (these can be eaten).
Make small, 3-5cm-deep holes in the soil spaced 10-15cm apart, with rows 20cm apart.
Plant one clove per hole, with the thick end at the bottom and the pointed end at the top.
Smooth over the soil and water in well.
Mulch with an organic mulch such as straw or lucerne.
Shoots should appear in 2-6 weeks.

How to Grow Garlic

Garlic plants may need watering during the growing season. Water when the soil is dry about 5cm below the surface (test this by scratching away a little soil with your finger). Water deeply in the early morning or late afternoon. Avoid watering the leaves of plants to avoid fungal diseases. Learn more about watering here.

If soil was well prepared no extra fertiliser should be necessary. Fertilising can result in excessive leaf growth at the expense of roots forming. In poor soil use a fertiliser low in nitrogen and high in phosphorus, such as blood and bone, applied at the recommended rate.

Hardneck varieties only - Remove scapes (flower stalks) at the base when they begin to curl to encourage bulb formation.

How to Harvest Garlic

Garlic should be ready to harvest in approximately 200-300 days.

Bulbs are ready to harvest when the foliage wilts and turns yellow and there are 4 to 6 green leaves remaining. Use a fork to gently lift the entire plant from the bed, shaking off the excess soil. Place the whole plants on wire racks or hang them in bunches, leaving them in a dry cool place for 3-10 weeks to cure. Softneck garlic can then be braided if desired. Trim the roots and stems back to 2.5cm and store in a cool dry place for up to 10 months.

Common Problems when Growing Garlic

Like all plants, garlic is susceptible to some pests, diseases and other problems. Below is a list of the most common problems gardeners encounter when growing garlic plants:

Aphids are small (2-4mm long) sap-sucking insects that congregate on the new shoots or the undersides of leaves. They can cause leaves to wilt or become discoloured, and also excrete honeydew which can attract ants and other insect pests. To manage aphids, remove them by spraying with a garden hose, apply a soap or alcohol spray, or encourage predatory insects to your garden. Read more about aphids here.
Bulbs not forming can be caused by harvesting too early, inconsistent watering or weather, planting bulbs or cloves that are too small, or too much nitrogen during the growing season. Plant varieties suited to your climate, do not over fertilise, water regularly and harvest after the leaves have started to die down.

If a single large bulb (a ‘round’) has formed, it can be eaten or replanted in autumn to grow into a bulb next season.
Rust (Puccinia sp.) is a fungal disease that causes brown to orange raised spots or patches to appear on foliage. Fungal spores are spread by wind or water to neighbouring plants, especially in temperatures of 10-20C and when humidity is high. To manage rust, space plants to avoid overcrowding, grow them in the recommended amount of light (eg full sun), do not over fertilise crops, remove dead plants and practice crop rotation. Read more about rust fungus here.
Onion thrips (Thrips tabaci) are flying insects less than 1.5mm long with slender pale yellow to light brown bodies. They suck sap from plants, leaving silver patches on the leaves and reducing the productivity and yield of plants. Thrips can live in the inner leaves and leaf folds of alliums, and may also infest bulbs. Wash thrips from affected plants using a garden hose, spread an organic mulch around plants, and encourage predatory mites and lacewings with companion planting.
Powdery mildew is caused by fungal spores reproducing on the leaves of plants. First showing as white spots on leaves, affected areas areas can spread quickly to cover the entire leaf surface. While rarely fatal, powdery mildew can reduce yields. Water plants at soil level (not on the leaves) to prevent spreading spores, allow good air flow between plants, remove affected leaves and if necessary spray with an appropriate fungicide or homemade spray. Read more here about powdery mildew here.
Slugs and snails are molluscs that feed on tender leaves and shoots, mostly at night, leaving slimy trails behind them. Control them by removing their hiding places, keeping free range poultry, collecting them by torchlight or by placing traps. Read more about slugs and snails here.