Family: Amaryllidaceae
Binomial name: Allium porrum
Life Cycle: biennial (usually grown as an annual)
Leeks can be grown year-round in most climates. Avoid planting in extremely hot or cold weather which can affect germination and growth. Use the table below to identify the best time of year to sow leeks in your climate.
JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Cool | ||||||||||||
Temperate | ||||||||||||
Sub-Tropical | ||||||||||||
Tropical | ||||||||||||
Arid |
Leek plants are best grown in full sun. Choose a location that will receive at least 6 hours of full sun each day.
Leek plants need a well drained soil enriched with plenty of organic matter. Prepare soil by weeding it thoroughly, digging it over to loosen it and adding aged animal manure or compost. Keep the area free of weeds until planting.
Leek seeds do not require any treatment (eg soaking, stratification) before sowing.
Leek seeds can be sown directly into the garden OR seedlings can be raised in trays or other containers and transplanted to the garden once established.
Tip: Leek seeds can also be sown in the less formal ‘scatter seed’ method. Simply roughen the soil, scatter seeds evenly over the surface, then smooth the soil over lightly to cover the seeds.
Tip: Leek seeds are quite small. Handle them carefully to avoid them blowing away or being washed away. Mix seeds with sand or fine potting mix prior to sowing or use a seed dispenser, damp toothpick or tweezers to help space them evenly. Press lightly into the surface after sowing so that the seeds make good contact with the soil. Take extra care to make sure seeds and seedlings don’t dry out. Read more about sowing small seeds here.
Leek 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. In poor soil or to give your plants an extra boost, application of a balanced fertiliser or one formulated for fruit and vegetables can be beneficial:
Optional: To give plants room to grow, thin seedlings when they are large enough to handle. Pull out any weak or small seedlings so plants are spaced about 12cm apart.
Optional: Leek plants can be blanched to improve tenderness and flavour. Exclude light around plants by hilling soil up around their bases, mulching thickly with straw or placing opaque containers around the plant. Learn more about blanching here.
Leeks should be ready to harvest in approximately 120-150 days.
Plants are ready to harvest when they are large enough to eat. Gently pull the whole plant from the ground and shake off any excess soil. Leeks are best left in the ground until needed. For short term storage, harvested leeks can be stored wrapped in a damp paper towel in a perforated plastic bag in the fridge.
Like all plants, leek is susceptible to some pests, diseases and other problems. Below is a list of the most common problems gardeners encounter when growing leek plants: