How to Grow Elephant Garlic
Grow Guide #2602
Binomial name: Allium ampeloprasum
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 Elephant Garlic (Allium ampeloprasum).
When to Plant Elephant Garlic
Elephant garlic is a cool season crop. Use the table below to identify the best time of year to plant elephant garlic in your climate.
Elephant Garlic plants are best grown in full sun. Choose a location that will receive at least 6 hours of full sun each day.
Elephant 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 Elephant Garlic
Elephant garlic cloves grow best when planted directly into the garden.
- Separate bulbs into individual cloves.
- Make small, 5cm-deep holes in the soil spaced 30cm apart, with rows 30cm 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 Elephant Garlic
Elephant 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.
How to Harvest Elephant Garlic
Elephant Garlic should be ready to harvest in approximately 280-320 days. Depending on growing conditions, plants can take two years to form full size bulbs.
Bulbs are ready to harvest once the plant has flowered and the flowers have dried. 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.
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 Elephant Garlic
Like all plants, elephant garlic is susceptible to some pests, diseases and other problems. Below is a list of the most common problems gardeners encounter when growing elephant 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.
- 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 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.
- Rotten bulbs are caused by pathogens entering bulbs after sitting in cold, wet soil, being temporarily waterlogged or being exposed to warm temperatures in winter. Bulbs may show obvious signs of rot, have no roots or shoots, or produce stunted yellow leaves but no flowers. Plant bulbs in free-draining soil, raised garden beds or containers; do not water bulbs over winter; and lift and store bulbs over winter if recommended for your climate.
- 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.