Growing Tomatoes on the Canadian Prairies

We garden in a zone 3b urban setting. Our gardening season can be quite short. Some years we can still have frost occur as late as the 6th of June, and can have a fall frost as early as September 7th. This gives us about 92 days to our growing season. This means we need to take the most of those days when growing tomatoes.

Canned or frozen tomatoes are a major staple in our house. We like to preserve lots of soups, salsa and sauces, so we need this crop to perform well.

Starting Tomatoes.

Tomato seedlings started in 6 cell tray

We start our tomatoes in early March. Place a seed into a 6 cell tray filled with a soilless potting mix and cover about 1/4 inch deep. Seeds will germinate in about 8-10 days without bottom heat.

Keep seedlings watered well. Do not let the soil dry out as at this stage as the plants are quite tender.

Transplant into 4 inch pot

As the plants grow, move them into a larger pot. We generally use a 4 inch pot. Remove the lower leaves and plant the seedling deeper. This encourages a larger root base for a strong healthy plant. Use a seedling fertilizer at half the recommended rate once a week. We typically grow indeterminate tomatoes. These are the staking type that continue to grow upwards until you snip off the top. They continually produce versus the determinate type that produce all at once.

When the risk of frost has passed it is time to harden off your tomatoes. Set them outside increasing their time outdoors each day, slowly exposing them to sunlight. Be careful not to expose them too quickly to afternoon sun as the leaves will easily sunburn at this stage.

Planting Out Tomatoes

Skim Milk powder to combat blossom end rot

Once all risk of frost has passed, you can prepare a planting hole, and add a stake. We use a trench that is deeper at one end. Then we add 1/2 cup of skim milk powder. This is a trick learned from my father in law to avoid issues with blossom end rot. I don’t know for sure that this works, but I do know we have never had blossom end rot in our garden.

Blossom end rot is a lack of calcium to the plant. Most often caused by irregular watering. When the roots get too much water at once they cannot pull nutrients from the soil. If your tomatoes look like this remove all the tomatoes affected. Mulch around your plants with grass clippings. Water regularly, that is the key. Blossom end rot is not contagious so the plant may turn around.

Next we prepare our plant. As all the little hairs on the stem will develop roots if they are in contact with dirt, we remove the lower 1/3rd of the leaves. We will then plant at an angle. This will help the plant develop a large root base to sustain a plant that will easily reach 7 feet.

Tomato Plant in a Trench

The plant is added to a trench containing some well rotted sheep manure. The root ball is in the deep area of the trench, the top part at the shallow end. Cover the plant with soil and water the plant. At this stage I also add a Jobes tomato fertilizer spike. This along with a bit of sheep manure to mulch keeps them happy for the season.

In a few days the tomato plant will be growing upright and can be attached to the stake. We use 6 foot vertical stakes that have been stabilized with bamboo canes to form a solid structure. Remove any leaves that may be touching the ground. Mulch with some dry grass clippings. This will keep the moisture in the soil and keep dirt from splashing onto the plant when watered.

Indeterminate tomato suckers

With the indeterminate tomato you will continue to pinch out the suckers. Those are the side shoots that grow at 45 degrees off the main stem. By removing them it’s less branching for the plant, producing one strong stem for concentrated fruit production.

There are so many varieties of tomatoes, we have a few tried and true and like to try something new each year. There truly is a tomato out there for everyone.

2 Responses to “Growing Tomatoes on the Canadian Prairies”

  1. I’m not a tomato grower but I know someone who is and I’ve forwarded this valuable information. Thanks again Murlo!