How to Grow the Best Tomatoes in Alberta


Learning how to grow tomatoes is incredibly rewarding and, for tomato lovers, there is NOTHING like a fresh off-the-vine-tomato.

Wondering exactly how to grow great tomatoes?

In this blog we will talk about where to grow tomatoes, how to water & fertilize tomatoes, and how to deal with tomato suckers.

Fun Facts About Tomatoes

Tomatoes are available in every size and almost every colour of the rainbow.

Tomatoes are originally a tropical plant. In their wild state, they had small berry-like fruit. 

Botanically, tomatoes are a fruit because they develop from a flower and seeds are encased by the resulting fruit.  We tend to consider tomatoes as vegetables because most tomatoes aren’t as sweet as a fruits like apples, peaches, or plums, and we use them in dishes that are savoury, such as pasta and pizza!

Tomatoes are simple to cross pollinate to create new varieties, and horticultural researchers have been breeding new kinds for decades! 

Over the last century, thousands of varieties have been developed for better flavour, storage, and texture; and in some cases to reduce acidity, increase the lycopene content, and produce different colours.

Where to Grow Tomatoes

Tomatoes thrive in hot, sunny places.

Knowing that tomatoes hail from the tropics gives clues as to how to grow them effectively. 

First, tomatoes like sunny, hot, humid growing conditions.  What does that look like? 

Here are some ideas:

  • Tomatoes need at least 6-8 hours of sunshine to thrive — the more sun, the better. That would mean an east, south, or western exposure; or a combination thereof.
  • Grow tomatoes in the hottest spot in your growing space like next to a wall that will reflect some heat — but be reasonable, you don’t want to scorch them.
  • If you have a greenhouse, that’s a great option for growing tomatoes, too.
  • Tomatoes also grow well in pots and in raised beds.  Again, thinking of their origin in the tropics, tomatoes love to keep their roots warm.  Raised beds and pots keep their toes toasty & happy.

How to Plant Tomatoes

Tomatoes grow well in pots, raised beds, and in the ground.

Healthy roots are foundational to healthy tomato plant growth. Tomatoes have shallow, fibrous roots that grow out laterally from their stem into the soil.

Tomato root damage can lead to Tomato Blossom End Rot.

Gently loosen tomato plants from their packs or pots to minimize root damage. If the roots are sticking to the sides of their small container, water them thoroughly, and that will help to ease them out.

Dig a hole 1.5 times the width of the tomato rootball, gently loosen the roots a bit, and carefully place the plant in the hole so the roots are in contact with the soil.

Fill in the space with soil and avoid packing soil against the roots being careful to not squish, squeeze, or crush the roots by pressing the roots down too hard. Loose soil has essential air spaces to hold water and nutrients for the plant.

I like to top off my tomato plantings with mulch. Mulch is beneficial to maintain soil moisture, contributes additional nutrients, and controls weed growth. Mulch will also reduce the root temperature, which is helpful during the hottest times of summer.

Place 7-8 cm (3″) of mulch around the base of the tomato. Keep the mulch away from the tomato stem to avoid rotting it. 

Related: What is Mulch? Making Gardening Magic with Mulch

Growing Tomatoes in Pots

Tomatoes grow well in pots, which are ideal for small yards, balconies, or patios.

The most common mistake to avoid when growing tomatoes in pots is planting them in a pot that is too small. Small pots make it difficult to keep the tomato well hydrated, especially when the weather is hot and the plant is growing rapidly.

Check labels to determine the mature size of the tomato. If the plant is expected to grow to 1 meter (3 feet) or higher, use a pot that is deep with a large diameter of at least 18″ or 22″ across the top. 

Smaller tomatoes will grow well in smaller pots, but I really wouldn’t go any smaller than a 14″ diameter pot because of the water demands.

Taking Care of Your Tomato Plants

Tomatoes do best with consistent care.

Tomatoes are heavy feeders and heavy drinkers.  What does that mean? Tomatoes experience exponential growth in the heat and they need consistent the water and fertilizer.

Grow tomatoes in a high quality soil with good water holding and draining capacity.  Soil  that doesn’t drain well will lead to root rot in tomatoes. 

Use mulch around the base of tomato plants to help hold in moisture and keep their roots cool. 

I recommend using mulch around the base of tomatoes everywhere:  in the ground, in raised beds, and in pots.  Any organic mulch that is a mix of chopped leaves, stems, and bark will work well here.

How much water should you put on your tomato plant?

Tomatoes grow best with consistent water.

Tomatoes grow best with consistent water. If they go through repeated cycles of severe wilting, their calcium transport system may become compromised and they may develop blossom end rot.

Related: 3 Strategies to Deal with Tomato Blossom End Rot

Uneven watering can also cause issues with flavour.

Check tomato soil hydration daily, especially on hot days, and water thoroughly if needed. I check my tomatoes by inserting the entire length of my index finger into the soil. If the soil is dry at the tip of my finger or the first knuckle, I water.

At the height of summer and on sunny days, the tomatoes in my raised beds get watered daily, even without checking.  That’s just part of my routine on hot days. 

If the weather is cloudy, I assess the soil, and if it is rainy, I definitely let the rain water them for me.

When tomato plants are large and growing in pots, I recommend that you water them until you see water beginning to seep out of the pot. 

How to Fertilize Tomatoes

Tomatoes grow best with regular fertilizer applications.

Tomatoes have high fertilizer requirement because they grow so rapidly.  Fertilize tomatoes weekly for maximum growth and fruit production.

There are many tomato fertilizer options on the market.  Look around and choose the one that works best for you and follow package directions.  There are some slow release fertilizers and tomato fertilizer spikes that work well too.

To Prune or Not to Prune Tomato Suckers?

Tomato suckers grow between the main tomato stem and tomato leaves.

Tomato suckers are extra stems that grow between the main tomato stem and tomato leaves.

There are no hard and fast rules anymore about whether tomato suckers need to be pinched out or not because the research is inconclusive. 

Some research says that tomatoes are more productive when the suckers are taken off, other research supports the opposite.  So, it is really a personal preference. See which works best for you.

Related: What to do with Tomato Suckers

In Conclusion

Tomatoes are one of the simplest garden vegetables to grow and a great place to start for any garden. Tomato be grown virtually anywhere as long as there is enough sun in your growing space. 

And for the flavour they add to the kitchen table, they are definitely worth the effort!

© Sharon Wallish Murphy, Gardening with Sharon

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