How to Grow Garlic Bulbs

Grow Guide #2272
Family: Amaryllidaceae
Binomial name: Allium sativum
Life Cycle: Perennial (usually grown as an annual)

This 'How to Grow' guide details everything a home gardener needs to know to plant, grow and care for Garlic (Allium sativum).

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 Plant Garlic

Garlic is a cool season crop. Use the table below to identify the best time of year to plant 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. Learn more about preparing soil for planting here. 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. 

  1. Separate bulbs into individual cloves. Do not plant very small cloves (these can be eaten).
  2. Make small, 3-5cm-deep holes in the soil spaced 10-15cm apart, with rows 20cm apart.
  3. Plant one clove per hole, with the thick end at the bottom and the pointed end at the top.
  4. Smooth over the soil and water in well.
  5. Mulch with an organic mulch such as straw or lucerne.
  6. 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. It is a good idea to harvest a single plant first to make sure a bulb has formed; if the bulb is small or unformed, leave the remaining plants for 2-3 weeks then harvest and check another bulb. The main period for bulb formation and enlargement is in the weeks leading up to harvest.

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
    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.
  • garlic bulb
    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 fungus
    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.
  • Leaves of an onion plant
    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
    Powdery mildew is caused by fungal spores reproducing on the leaves of plants. First showing as white spots on leaves, affected 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 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.
  • Flower bulb rot
    Rotten bulbs or corms are caused by pathogens entering bulbs or corms after sitting in cold, wet soil, being temporarily waterlogged or being exposed to warm temperatures in winter. They may show obvious signs of rot, have no roots or shoots, or produce stunted yellow leaves but no flowers. Plant bulbs and corms in free-draining soil, raised garden beds or containers; do not water while dormant; and lift and store them if recommended for your climate.
  • Slugs and Snails
    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.

Browse Garlic Bulbs

Garlic- Australian White (Bulb)

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Garlic- Colossus (Bulb)

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Garlic- Dynamite (Bulb)

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Garlic- Early Purple (Bulb)

Garlic- Early Purple (Bulb)

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