Leeks need looking after carefully, because they grow slowly and don't have a lot of foliage. They do not form bulbs the way onions do but instead develop thick cylindrical stalks.

Water Needs


Leeks grow best in moist soil. Give the plants constant moisture and apply a mulch.

Fertilizer Needs


Moderate nitrogen. Moderate potassium. Moderate phosphorous.

Leeks aren't a very hungry plant.

Watering, regularly

Water, 0.5 inch(es), regularly, 2 times a week

Keep the soil moist with regular watering.

Watering also depends on your local weather; don't water if it's raining, or water more frequently if it's dry. Just be sure to keep soil moist for the best crop. The best way to know how much moisture is in your soil is to feel 2" below the soil line. If it's dry, water.

Weeding, regularly

regularly, every 3 weeks

The lack of foliage makes young leeks very vulnerable to competition from weeds. It is very important to keep them well weeded, so they don’t get overwhelmed. Leeks are quite shallow rooted, so be careful if weeding with a hoe (it’s safer to hand weed).

Protecting, while danger of frost

Mulch, 4 inch(es), while danger of frost, 1 time

Mulch is essential in areas where winter temperatures drop below 10˚ Fahrenheit. It not only protects the plants from cold, but also stabilizes the soil temperature. This prevents frost heaving, which can damage the roots. It’s best to apply a mulch while the soil is still warm, to hold in the heat.

Side Dressing, when 3in tall

Compost tea, 3 gallon(s) per 100 sq. ft., when 3in tall, 1 time

Leeks are often in the soil when it’s cold and many nutrients aren’t easily available. Give them a feed of diluted compost tea or liquid kelp (use as directed) as soon as they are well established.

Side Dressing, when 12in tall

Compost tea, 5 gallon(s) per 100 sq. ft., when 12in tall, every 4 weeks

Feed them with compost tea again when they are about a foot tall and then every 4 weeks after that.

You could also use liquid kelp or fish emulsion instead (apply as directed).

Thinning, during fruit production

during fruit production, 1 time a week

During the growing season thin Leeks to the variety requirements. You may continually thin which will allow you to eat tender young Leeks. Thinning Leeks, before they reach full size, is a process that can be utilized until the crop reaches full maturity. Harvest by thinning alternate plants, as this gives the remaining plants more room to grow. Just be sure you don’t disturb their roots. Alternatively you could take the largest plants first, leaving the others to size up.

Side Dressing, before harvest

Soil, 4 inch(es), before harvest, 1 time

Blanching: Leeks are often blanched to get a longer area of white stem, as this is considered superior to the green part. Blanching is usually done with soil, either by hilling up the stems (to just below where the leaves start), or filling up the trench they are growing in. Some gardeners wrap corrugated cardboard collars around the plants before blanching to prevent soil getting lodged between the leaves (no one likes gritty Leeks).

You can also blanch the stems with a deep mulch (4"), which has the advantage of not being gritty.

Side Dressing, to conserve moisture

Mulch, 2 inch(es), to conserve moisture, 1 time

Leeks don’t cast much shade, so they are vulnerable to weeds and the soil is prone to drying out in sunny weather. A layer of mulch helps the soil retain moisture, keeps down weeds and is a source of nutrients for the soil.