Leek

Family: Amaryllidaceae

Genus: Allium

Species: porrum

History

Leeks, a cool-season favourite, were cultivated by ancient Egyptians and prized by Romans for their refined flavour. The national emblem of Wales, leeks were brought to Australia by British settlers. Their mild, sweet flavour and cold-hardiness make them a reliable addition to any winter vegetable bed.

Sowing Calendar

Best Months to Plant – Leek
Climate ZoneJanFebMarAprMayJunJulAugSepOctNovDec
Cool/Mountain
Temperate
Arid
Subtropical
Tropical
Cool/Mountain – Leek
MethodJanFebMarAprMayJunJulAugSepOctNovDec
Start in trays
Plant out transplants
Direct sow
Temperate – Leek
MethodJanFebMarAprMayJunJulAugSepOctNovDec
Start in trays
Plant out transplants
Direct sow
Arid – Leek
MethodJanFebMarAprMayJunJulAugSepOctNovDec
Start in trays
Plant out transplants
Direct sow
Subtropical – Leek
MethodJanFebMarAprMayJunJulAugSepOctNovDec
Start in trays
Plant out transplants
Direct sow
Tropical – Leek
MethodJanFebMarAprMayJunJulAugSepOctNovDec
Start in trays
Plant out transplants
Direct sow

Where to Plant

Containers & Pots

Containers & Pots
• Portable planting vessels suited for patios, balconies, and small areas
• Provide complete control over soil composition and drainage
• Great for herbs, greens, compact vegetables, or ornamental plants
• Allow plants to be moved to follow sun, shade, or seasonal conditions

Shady Spots & Herb Gardens

Shady Spots & Herb Gardens
• Areas receiving dappled or indirect sunlight, often near trees or buildings
• Best for shade-tolerant herbs like mint, parsley, or greens like spinach
• Helps prevent sun stress and conserves moisture
• Often used in cooler corners of the garden

Edges

Edges
• Narrow growing spaces along borders, fences, or pathways
• Perfect for low-growing or decorative plants like alyssum or herbs
• Helps soften garden boundaries and attract beneficial insects
• Makes efficient use of underutilised garden space

Borders & Companion Rows

Borders & Companion Rows
• Found along the edges of garden beds, paths, or between main crops
• Ideal for herbs, flowers, or pest-repelling plants that support the main crop
• Helps attract pollinators and beneficial insects
• Makes good use of smaller spaces and improves overall garden health

Pre-treatment

None Identified

There are no pre treatments required for germination.

Sowing Method

Start in Trays

• Fill seed trays or punnets with quality seed-raising mix
• Sow seeds at the correct depth—refer to seed packet for guidance
• Place trays in a warm, sheltered location with good light
• Mist or bottom-water to avoid disturbing small seeds
• Transplant seedlings once they develop 2–4 true leaves

Direct Sow

• Sow seeds directly into prepared garden soil or outdoor containers
• Best for plants that dislike transplanting, such as root vegetables and beans
• Loosen soil and remove weeds before sowing
• Sow at the recommended depth and spacing, then water gently
• Keep the area moist until germination and thin seedlings if needed

Watering

High

• Requires consistently moist soil, particularly during warm or dry periods
• Best suited to shallow-rooted or leafy plants such as lettuces, leafy greens, and tropical herbs
• May need daily watering in hot, exposed locations or sandy soils
• Avoid letting soil dry out—wilting may occur quickly if moisture is lost
• Use mulch and drip irrigation to maintain even moisture levels

Fertilisation

Frost

Frost Tolerant

These plants can tolerate light to moderate frosts and may survive through cooler seasons.

Maintenance and Harvesting

Leeks require deep planting and hilling up to blanch the stems. Regular watering and nitrogen-rich feeds promote strong growth. Keep beds weed-free and remove flower stalks to prolong harvesting.

Pests and Diseases

Downy mildew

Downy mildew causes pale yellow blotches on upper leaf surfaces with grey‑purple fuzz beneath, spreading fast in cool, moist weather. Heavily infected leaves collapse, slowing growth and yield.

Choose sunny, well‑ventilated positions, water early so foliage dries quickly, and remove infected leaves promptly. Organic options include copper and bio‑fungicides (phosphorous acid salts). For severe pressure, rotate chemical fungicide modes to prevent resistance.

Thrips

Thrips are slender insects that rasp and suck plant tissues, leaving silvery streaks and distorted growth on leaves and flowers. They can also transmit plant viruses.

Use blue or yellow sticky traps to monitor and reduce numbers, weed around beds, and encourage beneficials like minute pirate bugs. Neem oil and insecticidal soap offer organic suppression. If needed, use registered insecticides and rotate modes of action to avoid resistance.

Rust

Rust diseases produce raised orange‑brown pustules on leaves and stems. Spores disperse easily on wind and water, causing repeated reinfection and gradual weakening of plants.

Remove infected material and avoid wetting foliage. Grow resistant varieties where possible and rotate crops. Organic sulfur or copper sprays can protect new growth; systemic fungicides are a chemical fallback if rust persists.

Damping off (seedlings)

Damping‑off is a soil‑borne disease that attacks seeds and seedlings, causing poor germination, sudden collapse, or pinched, water‑soaked stems at soil level. It thrives in cool, wet, stagnant conditions.

Sow into fresh, clean seed‑raising mix; avoid reusing contaminated trays. Provide warmth, light, and airflow; water lightly and allow the surface to dry between waterings. A light dusting of cinnamon or chamomile tea is a gentle organic measure; fungicidal drenches are rarely necessary for home growers when hygiene is good.

Leaf miners

Leaf miners can affect plant health and yields in home gardens. Typical symptoms include slowed growth, discolouration, and reduced productivity, often triggered by weather, nutrition, or cultural conditions.

Start with cultural fixes: rotate crops, improve soil with compost, water consistently, and choose resistant varieties. Organic sprays or amendments can reduce severity; chemical options are a last resort and should be used carefully and in accordance with labels.

Neck rot / storage rots

Neck rot / storage rots can affect plant health and yields in home gardens. Typical symptoms include slowed growth, discolouration, and reduced productivity, often triggered by weather, nutrition, or cultural conditions.

Start with cultural fixes: rotate crops, improve soil with compost, water consistently, and choose resistant varieties. Organic sprays or amendments can reduce severity; chemical options are a last resort and should be used carefully and in accordance with labels.

White rot

White rot can affect plant health and yields in home gardens. Typical symptoms include slowed growth, discolouration, and reduced productivity, often triggered by weather, nutrition, or cultural conditions.

Start with cultural fixes: rotate crops, improve soil with compost, water consistently, and choose resistant varieties. Organic sprays or amendments can reduce severity; chemical options are a last resort and should be used carefully and in accordance with labels.

Growing Tips

• Thin shanks from poor feeding or crowding can affect Leek. Improve soil fertility with compost and keep the soil evenly moist to encourage strong growth.
• Leek is prone to sun-green (short blanch) without hilling or collars. Good cultural practices such as timely sowing, consistent care, and soil preparation can help manage this.

Browse Leek Seeds