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April 6, 2017

Growing Tomatoes in Cold Climate

Here are 9 simple tips for growing tomatoes successfully in cold climate and harvest sun ripe tomatoes in the summer. Happy tomato growing!

Nothing says summer like a freshly picked, ripe tomato from the vine. However, in a cold climate and short growing season, it does not happen very often, if at all. Most tomato growers around here pick green tomatoes in the fall and after ripen them indoors. Our summer seems to be just too short and too cool to ripen tomatoes.

We have good news for you today: With these 9 simple tips you too can harvest ripe tomatoes in the summer.

Tomatoes are a summer crop.ย  They die when freezing weather occurs, but they also do not like it cold, windy, and wet. In order to grow tomatoes and get them to ripen, they need a warm, dry spot. However, with summer night temperatures dropping under 10C (50F) tomatoes will be shivering. What to do? Here are some simple tips for growing tomatoes in cold climate and harvest ripe tomatoes in the summer.

Note: To achieve ripe tomatoes in a greenhouse is much easier thanย it is outdoors, and I think it is the best way to go for us northern growers. Still, in this post, I will concentrate on outdoor growing and just give some tips on greenhouse growing.

1. Choose an early tomato variety

Not all tomatoes are the same. Some ripen faster and tolerate cool weather better than others. Generally determinate or dwarf tomatoes are earlier and better suited for outdoor growing. Casey’s heirloom tomatoes catalog has a guide to the best (non-cherry) tomatoes to grow outdoors in Calgary (zone 3) and also a guide to the best tomatoes to grow in pots. You might find your favorite variety on that list.

Other seed suppliers have great tomatoes for a short and cool season, too. Just make sure they are early. It is best to get seeds from local growers, or a climate similar to yours. Those tomato plants have already been adjusted to the weather and will grow and produce better.

Growing Tomatoes in Cold Climate

2. Start tomatoes about 6 – 8 weeks prior to planting them out

You want the seedling to be just about setting out buds. Not bloomed yet. In our area, our last frost date is May 26. Since tomatoes do not tolerate any frost, you might have to wait till June 1 to plant them outdoors. Start the seeds indoors end of March to mid-April. If you have grow lights or a very sunny window, the seedlings will grow fasterย soย plant them later.

In most cases, it does not workย to start seedlings earlier to get ripe tomatoes earlier. If the seedling is overgrown, it will suffer, and you will get ripe tomatoes later. Read all about starting tomatoes from seeds here.

If you do have a greenhouse, and or use protection (see below) you might be able to plant them a few weeks earlier.

Growing Tomatoes in Cold Climate

3. Choose a sheltered location

Location is everything when it comes to growing tomatoes. If you have a spot in your garden that is too hot for most crops, it might be just right for tomatoes. If you do not have a warm spot in your garden, but on your deck, tomatoes can be grown in pots or grow bags. We grow ours in grow bags on our driveway. The heat from the concrete and the black bags will help to keep the heat-loving plants warm. See how to grow in grow bags.

Note, if you are in a warm climate, tomatoes might be too hot in containers on yurt driveway. We are speaking here about a cool climate.

Growing Tomatoes in Cold Climate

4. Add manure to the soil while planting

Manure has the tendency to warm up the soil. Especially horse manure is known for that. Just make sure the manure is composted. Later in the season, water with compost tea. The boost will help the plants to grow better and mature earlier.

Growing Tomatoes in Cold Climate

A tip that I just learned from a Russian grower is interesting enough to share. He uses freshly cat grass (hey) and piles it up so that the hey starts to compost, get warm. At this point, he layers the hot compost around the tomato plants. It is not hot enough to harm the plant but does give additional heat to the plants.

5. Protect young tomato plants

You get what you pay for, or in this case what you invest in. To plant tomatoes in an open field, and leave them to the elements, will not lead to early ripe tomatoes. Give them as much protection as you can give outdoors. I like the Plant Protection Blanket, it is light weighted and can be left on for days, as needed. You can cover a tomato bed with it, or wrap an individual plant.

Built a wind barrierย for the tomatoes out of recycled windows. This simple frame works very well in creating a micro-climate.

You can also use a Kozy Coats Water Filled Garden Teepee, add water, and place the filled teepees over the plants. The Kozy Coat becomes an igloo, keeping in the heat and warmth from the soil.

Growing Tomatoes in Cold Climate

6. Add thermal mass

The Kozy Coat already works as protection and thermal mass, or you can simply put a milk jar filled with water next to the plant. Rocks work the same way, build a little wall behind your plants, the rocks will heat up during the day and give the heat back at night, giving some wind protection as well.

Thermal mass seems to be even more important in a greenhouse (See water tank in a greenhouse). A plastic covered greenhouse gives you only about 3 degrees at night but heats up the place beyond comfortable during the day. Theย fluctuationย  in temperatureis very hard on plants. Thermal mass helps to regulate it.

Growing Tomatoes in Cold Climate

7. Hand pollinate

Pollinating tomato plants is very easy, just shake the plants, or the flower cluster a bit, that’s it. Sure, wind or insects can do it for you, but while waiting for them you might lose some precious ripening time.

Growing Tomatoes in Cold Climate

8. Water with stagnant water

Watering plants with tap water may or may not harm beneficial bacteria in the soil, but it sure is to cold for heat loving plants. It is better to use stagnant water that is warmed up from the sun. That way the plants will not go into shock every time you water.

Growing Tomatoes in Cold Climate

9. Prune your plant

Most determinate plants do not need pruning. Still, if you have very big tomato clusters, cut them back some, they will ripen faster. If the plant is indeterminate, definitely prune it back. See whetherย to prune or not to prune tomato plants. Outdoors you want to prune the plants even more than in a greenhouse. You will get less fruit, but they will be bigger and ripen faster. It’s the better choice.

Growing Tomatoes in Cold Climate

Here you have it, 9 simple tips to grow tomatoes successfully in cold climate and harvest ripe tomatoes in the summer. The more protection, love, and care you give, the earlierย the plant will grow and ripen.

However, for growing ripe tomatoes around here some summers are better than others. If the weather is just too cool, and it snows in between, do not beat yourself up about it. Tomatoes do ripen nicely indoors.

Happy tomato growing!

If you like this post donโ€™t forget to subscribe to Northern Homestead and follow us on Instagram,ย Facebook, or Pinterest for the latest updates.

More Growing Tomatoes Posts You Might Enjoy:

When and How to Start Tomato Seeds Indoors

When and How to Start Tomato Seeds Indoors

To prune or not to prune tomato plants is an option. Not all tomatoes need pruning, except for the bottom leafs and at the end of the growing season.

To Prune or Not to Prune Tomato Plants

Learn how to support vine and bush type tomatoes in the greenhouse and in the garden. We share our favorite methods that have worked great for many years.

How to Support Tomato Plants

How to Grow Tomatoes Indoors

Complete Guide on How To Grow Tomatoes Indoors

Common tomato leaf diseases

Common tomato leaf diseases

How to start tomatoes from seeds using a no fail method that involves less work. This method has worked for us for many years.

How to Start Tomatoes from Seeds

Bull's Heart Heirloom Tomato Variety

Bull’s Heart Heirloom Tomato Variety

It is always a very exciting day when tomato plants can go into the ground! Here a complete guide on how to transplant tomato plants into the ground.

Transplanting Tomato Plants into the Ground

Growing Tomatoes Summer Update

Growing Tomatoes Summer Update

Heirloom tomato varieties we grow in a northern garden in Alberta, Canada. Many have become our favorites in taste and production.

Heirloom Tomato Varieties We Grow In a Northern Garden

Reader Interactions

Comments

  1. Gentle Joy says

    June 10, 2015 at

    Good advice… we usually have great tomatoes.. just not enough of them, but with all of the rain and no sun this year, these tips may come in handy. Thank you.

    Reply
    • Anna says

      June 10, 2015 at

      Well, it all depends an the weather, doesn’t it? Tomatoes do not like rain all that much. Hope you can give them some rain protection. Happy tomato growing!

      Reply
  2. Marla says

    June 17, 2015 at

    Good article. Luckily I live where we have a longer summer so I don’t have these problem, but your ideas sound very feasible and I love your pictures. Shared on twitter & pinned. Visiting from Homestead Blog Hop.

    Reply
    • Anna says

      June 17, 2015 at

      Long summers also means you can use some of those tips to grow food in the off season ;). I would not grow tomatoes, but cabbage and carrots and spinach. Happy gardening!

      Reply
  3. John Ghitan says

    January 22, 2019 at

    Great info! Thx! Am building a small bungalow and have created a landscape design that incorporates a demi-green house backing onto the south wall of my garage, specifically for tomatoes. Any further tips on greenhouse growing?
    Thx again,
    John

    Reply
    • Anna says

      January 25, 2019 at

      Congratulations on your new greenhouse. We do have many greenhouse growing tips. Find them here: https://northernhomestead.com/category/greenhouse/

      Reply
  4. Muhammad Junaid says

    November 16, 2019 at

    Very interesting and informative, we do like the tomatoe cultivation in our home from childhood and feel very delighted to see when our garden tomatoes turn red from green.

    Reply
    • Anna says

      November 18, 2019 at

      It’s a special moment, every time. Enjoy and happy tomato growing.

      Reply

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