How To Grow Leeks In Canada

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Are you wondering how to grow leeks in Canada? This garden Canada article is going to look at exactly how to grow leeks in a Canadian garden from start to finish. With a particular emphasis on how to get a large leek “bulb”.

Growing leeks in canada
Growing leeks in canada

If you are new to this blog my name is Ashley and I am a soil scientist. I am located in a Canadian Zone 3 and a USDA Zone 4. I write articles, make YouTube videos, Instagram & Facebook posts all designed for Canadians and Cold Climate gardeners using science-based methods. If you are looking for anything specific be sure to let me know in the comments down below.

It’s important that we don’t call a leek an onion. Leeks are planted and cared for much different than that of an onion plant. For more information on how to care for onions in Canada then check out the Gardening Canada article all about growing onions. 

For those of you that are just looking for leek varieties that grow best in Canada. Check out this list here of some of my favourites that I have grown here in Canada. They yield great results and have a white variety of different flavours and colours. 

What To Start Leek Seeds In Canada

Leak seeds need to be started in March. This means for a majority of Canadian gardeners leeks will need to be started indoors. The good news is that leek seedlings do not take up much space. This means they are not as labour-intensive as that of a tomato plant. 

When you start your leek seeds indoors you will want to provide them with some lighting. They will not need as intense lighting as that of a tomato plant. However, It’s unlikely that you were experiencing any sort of laginess in a leek seed. 

Transplanting Leeks Outdoors In Canada

When you transplant your leek seedlings outdoors you will want to harden them off just like with any plant. The learning process can take anywhere from 1 to 2 weeks. For more information on how to harden off plants be sure to check out this Gardening Canada video or article for guidance.

You’ll want to plant your leeks outdoors when the last threat of frost has passed. Look up the last frost date for your region to determine what day this may be. The earlier you get them outside the better because it will help them establish themselves before any pests come to the area.

With any plant, you want to determine the supplier’s recommended spacing. With leeks, it is generally around 30 cm between each plant. When it comes to the depth you’ll want to dig a hole that is 20 cm deep. Then place the leek seedling inside and give it water. The key is not to fill in the hole.

Over time the weathering of the swale will fill in the remainder of the hole. However, it will be filled in loosely. This will give the leek a head start when it comes to developing the stock. Another method to ensure you get a substantial stock on your leek plant is through hilling.

The hilling process of a leek will be similar to that of the hilling process of a tomato. All you need to do is use soil or mulch and hill around the leek as it grows. The additional soil piled up around the stem of the plant will ensure a larger leek stock.

When you grow leeks in Canada it is important to remember to watch for frost warnings is key. Consider covering the crop when there is a threat of frost in your area.

Fertilizer for leek plants

When it comes to fertilizer you want to just use a regular all-purpose. Stay away from things like bloom formulas for example. You can also simply just top dress with manure or compost. Onions have a high affinity for sulphur and leeks do have a slight affinity for sulphur. The use of manure will help ensure that sulphur is provided in a high enough quantity for the plant’s needs.

There you have a complete guide to growing leeks in Canada. If you’re a Canadian gardener that is deciding to grow leeks for the first time you’ll have to let me know in the comments down below. These are a family favourite for me because they are not as intensely flavoured as an onion. Fun fact leeks are part of the asparagus family and are in no way related to onions.