Growing Leeks in South Australia
This lovely cool-weather crop is a member of the onion family. Its sweet, mild flavour makes it a useful and versatile addition to any vegetable garden. Leeks are easy and fuss-free to grow and can be left in the ground for up to 12 months in cool weather. In South Australia, they can be planted in autumn or spring. Autumn-planted leeks will grow through winter and be ready to harvest in early spring, while the spring-planted ones will be ready for harvest in late summer and autumn.
Don’t allow your soil to dry out or become too wet. Leeks like a nice, even amount of moisture throughout their growing season.
Leeks prefer full sun, but will tolerate some shade. If you’re planting in autumn, then make sure they get all the sun they can. If you’re planting in spring, then a little shade will help protect them from the harsh summer sun.
Add some compost, well-rotted manure and lime to your soil. Leeks like rich, well-draining soil with plenty of nitrogen.
Spring-planted leeks will be smaller than autumn-planted leeks. Sow seeds every 4 weeks to prolong the harvest.
Leeks are usually sown in pots and then transplanted into the garden once they are big enough. Sprinkle the seeds over the soil, cover them lightly, and water well. Put them in a warm, light spot and be sure to keep the soil moist while the seeds germinate.
Seedlings can be planted as soon as the weather starts to cool.
Plant your seedlings into 150 mm deep holes. Backfill the holes with soil or compost as the leeks grow. This will help to blanch the lower part of the stem. Seedlings are often clumped when you buy them and need to be separated before planting. Simply remove them from their container and rinse the soil off. Once the soil is off, they should separate easily. Trim the tops of the leaves to help your plants transplant more easily.
If you would like a larger section of the stem to be blanched, then cover the stems for a couple of weeks before you harvest them. Simply place a barrier around the stem and secure it. Keeping the stems away from sunlight makes them whiter. Newspaper, or toilet rolls work well, but feel free to use whatever you have on hand.
Weed well around your leeks. They don’t like to compete for nutrients and space.
Keep the soil moist, but not too wet. The rainy, South Australian winters should do most of the watering work for you, but keep an eye on your leeks and make sure the soil doesn’t dry out.
Feed your leeks every 4-6 weeks. They like a fair amount of nitrogen, so a nitrogen-rich organic fertilizer or even some manure tea are good options.
Mulching leeks helps to keep the soil moist and coil. Apply a generous layer of organic mulch such as lucerne or sugarcane. For young seedlings, a mulch of around 1 cm should be enough, but you can increase the mulch to around 4 cm as they grow. Remember to top up your mulch throughout the growing season, as it does tend to break down.
Use a gardening-fork to gently lift the leeks out of the soil or use a sharp knife to cut the stems off below the soil. Leeks keep well in the soil, so harvest them as needed.