Leek is a long-growing and relatively low-maintenance vegetable with many culinary uses. It is a plant that you can install in early spring and easily put into the back of your mind until fall. There is one crucial step in mid-summer that I will get into, but other than that, it is a great low-maintenance vegetable.
Leek come in a variety of types, as illustrated in the photo above. Some have thicker, fatter white parts, some long and skinny and some have a bluish tint to the leaves. You may also find that some leek take longer to mature than others. I actually found a great seed source at Territorial Seed where they offer a Leek Succession Pack. This is a combination of 3 seed types, one called Zermatt which is a quick maturing leek, suitable for baby leek production. Hannibal takes a little longer than Zermatt, giving you your mid-season leek. The final seed in the pack is Bandit, which lasts late into fall. This excellent combination gives you leek throughout the growing season.
Leek can take a full 120 days to develop depending on the variety. Growing leek from seed also requires an additional 10-21 days for the seed to germinate. Plan to start your leek seeds indoors in mid-February (for Zone 5) in order give them enough time to mature. If using a succession program as mentioned above be sure to label each variety and note when it will be ready. Leek grow quickly indoors with grow lights. Keep trimmed to a 6-8″ height while indoors to encourage root growth. If you will not be starting from seed, many seed companies will ship leek plants in early spring directly to you. They are ready to plant, and a great option when seed starting is not an option.
Plant outdoors in late April/early May (Zone 5). Leek can withstand cooler temperatures in spring, but cover if any chance of frost occurs. When planting leek, first prepare an 8″ deep trench . Mix in a well-balanced organic fertilizer or compost at the rate specified for the size of the bed. Plant your leek at the bottom of the trench and bury at least half the plant in the ground. Your plant spacing should reflect the size of leek that you want to produce. For smaller, thinner or baby leek, plant about 4″ apart. For larger, fully developed leek, give the plants 8-10″ of space. Water thoroughly after planting and place any necessary animal protection around the plants. Tip: birds may try to pull leek seedlings out of the ground when first planted. Some temporary fencing works well to deter them.
Now, for the most part, you can ignore your leek. Aside from regular watering, they don’t need much else. There is one critical step, however, to developing a long white, useable section of leek.
Remember that trench which you planted your leek into? Once your leek has grown to a height of 18-24″, go ahead and fill that trench in with dirt. This will occur approximately in late June/early July. Bury your leek but leave at least 4-6″ of leek leaves exposed at the top.
The remaining leek that you have buried will turn white underground, and believe me, the part above ground will grow to heights and widths of 2-3′. Leek grow without any fuss or hoopla. One minute they are tiny little grass like structures and the next time you look they have turned into rather large, unassuming plants.
I have found leek to be a good wind barrier for other, more sensitive plants. It works well to protect green beans, lettuce and peppers as a companion plant to block strong winds. It is sturdy and strong with stiff fan like leaves that act as a natural fence.
Harvest and Use
Harvesting leek may start as early as August and may go all the way till December. The variety you grow and weather will be the determining factors. Leek can survive in the ground down to 5 degrees Fahrenheit. Now, I’m not too crazy about the idea of harvesting anything in temperatures of 5 degrees, but hey, good to know. I generally harvest my final leek in milder October temperatures of 40-50 degrees. I harvest smaller leek throughout the summer as needed.
Always dig leek with a shovel. Attempting to pull them out will result in broken leek and half of it still in the ground (yes I have done this). Dig around the plant and gently loosen it from the ground. Shake off the excess dirt and place into a large container for washing. I recommend washing leek outdoors unless you want to clog your drains with dirt. Leek hold a lot of dirt in their roots and layers, so you want to remove that outside.
After washing off the initial dirt, trim your leek for storage. Trim the excess roots, and cut the large fan leaves at an angle just above the usable area of the leek.
After trimming, wash once more before bringing indoors. Store leek in the refrigerator. They will last about 2 weeks in the fridge when trimmed and clean. Or, like I did, you can use them right away for some tasty meals. To cut leek for use, you will first want to cut off any excess leaves. Then, slice the leek lengthwise, leaving the root end intact. Wash the leek, yet again, separating the layers as you wash to remove the dirt inside. Then you may cut off the root end and slice your leek as needed.
Here are links to 2 fantastic recipes I just made with my leek harvest. Leek are a wonderfully versatile vegetable. You can use them to add a mild onion flavor to any dish, but their real flavor comes out when they are slowly caramelized. Sweet, creamy and savory all at once, the flavor is really delicious.