Freezing weather kill plants in the garden, right? Well, it depends. Plants hold up very differently to frost. In this post, we share a picture and video comparison on how different plants survive frost. It was very interesting to observe it first hand.
Why it is important to know how different plants survive frost
Growing a garden in the northern cold climate we constantly deal with frost. We can have frost as late as June, and as early as August, even though our official frost-free dates are around May 26 – Sep. 9.
Knowing how different plants react to frost helps us to start hardy plants as early as we possibly can, see when to plant what. It also helps us in an event of sudden frost to cover and protect only those plants that actually need protection, see protection from frost. It also helps us to relax, when there is nothing in the garden that frost could damage.
Picture comparison on how different plants survived the frost
The temperature outside dropped to -6 °C = 21.2 °F, and -2 °C = 28.4 °F in the greenhouse. That is cold! We took the pictures after the frost in the morning and a few days later; cold days!
See what happened.
All summer crops froze
Summer crops freeze very easily. In the greenhouse, the temperature did not drop as much as outside, but the plants were all still frozen. The first picture in the collage was taken on the first morning after the frost, the second a few days later.
Summer crops are: Beans, Basel, Cantaloupe, Corn, Cucumber, Eggplant, Okra, Bell & Chile Peppers, Potato leave, Pumpkin, Squash, Sweet Potato, Tomato, Watermelon, Zucchini …
All of these plants need frost protection, or they will freeze.
Fruit does not freeze right away
Even though the cucumber plant froze, the fruit did not. The same happened with the tomatoes. I harvested the last ones after the little frost in the greenhouse. However, heavy frost would damage the fruit, too. In the video below you will see that the fruit did not hold -3 °C.
If fruit like tomatoes and peppers freezes, it can still be harvested right away. Frozen fruit can also be preserved in the freezer for later use. Just make sure not to let it thaw in between of harvesting and freezing.
Young plants do not freeze as easily as mature plants
I heard about this before, but to see the huge difference between some young lettuce plants and the mature ones was amazing. Hard to believe that this lettuce survived, uncovered, -6 °C = 21.2 °F!
It means that lettuce can be planted long before the last frost date.
Winter crops are hardy
Kale is probably the most frost-resistant plant and also the most nutritional vegetable there is. The combination of these two astonishes me. The first picture in the collage was taken on the first morning after the frost, the second a few days later from a different kale plant, but they survived the same.
However, kale does have its limits. Read more in our January garden update.
Spinach not only stands frost but also continues to grow. The first picture in the collage was taken on the first morning after the frost, the second a few days later. We grow overwintering spinach here in Zone 3. Plant some in late summer for early greens in spring. The plants are only covered with snow and continue to grow after -40 degrees winters.
Again the first picture of the kohlrabi plant in the collage was taken on the first morning after the frost, the second a few days later. Chives, Fennel, Garlic, Onions, Peas, Radish and Strawberry are very hardy. Followed by Broccoli, Brussels Sprouts, Cabbage, Cauliflower, Kohlrabi, Lettuce, Pak Choi, Perennial Herbs, Radicchio, Rhubarb, and Spinach. Artichoke, Celery, and Leek may need a little more protection.
Root crops can stand some frost
Beets and carrots will survive in the ground as long as the ground is not frozen. The first picture in the collage was taken on the first morning after the frost, the second a few days later.
Potatoes are very hardy as well, however, the leaves will freeze. We always harvest potatoes after the frost in late September, early October after the frost has killed the leaves and the potatoes build some mature skin.
Carrots tend to become even sweeter. When covered, carrots can be left in the ground over the winter, read more: Growing winter carrots in a cold climate.
Some flowers are hardy to frost
Snapdragons are hardy flowers. I was amazed to see that even the blossoms that looked solid frozen in the morning, recovered nicely.
And one more first picture in the collage that was taken on the first morning after the frost, the second a few days later.
Hardy flowers: Alyssum, Anchusa, Centaurea, Dracaena, Dusty Miller, Larkspur, Nigella, Pansy, Snapdragon, Sweet Pea, Forget-Me-Not, Lavender, Petunia, Roses, Violet.
Some common summer flowers: African Daisy, Asters, Begonia, Bidens, Chrysanthemum, Dahlia, Fuchsia, Geranium, Hibiscus, Jasmine, Marguerite Daisy, Marigold, Mecardonia, Millet, Morning Glory, Napa Valley Fern, Nasturtium, Pentas, Sunflower, Tropical Hibiscus, Tropical Water Plants, Zinnia. All of this plants need frost protection or they will freeze.
A video update on how plants survive frost
Here is a short video on how different plants survive frost. We show the huge difference between summer and winter crops in the garden. If you can’t see the video, go here.
Hope this helps you to see the big potential winter crops have in a cold climate garden. Many plant varieties do not just survive but thrive after freezing temperatures arrive. Cabbage family plants and root vegetables tend to only get sweeter and better.
Inspiring books for winter gardening:
The Winter Harvest Handbook; Backyard Winter Gardening; Year-Round Vegetable Gardening.
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Wonderful post – there’s a lot to learn about gardening and the affects of frost on plants – vegies is very important – well done! So delighted you shared with Home and Garden Thursday,
Kathy
This is my first year with a greenhouse, my husband bought me a 10×12 kit and it just went up last week. It is not heated, no fan etc. but want to learn what I need or don’t need. I will learn a lot from your blogs. Thank you for sharing.
Congrats on the greenhouse! You will learn quickly and it is a lot of fun!
I live in Northern Wisconsin. What kind of grapes are you growing? Thank you. Kay
We grow the Valiant grape. It is a heave producer and always ripens in our short summer. The fruit gets tastier with frost. In our greenhouse, we also have a young Somerset Seedless Grapes. Not sure how it would do outside, we plan to move it out next spring.
Thanks so much. I am new to gardening in a place of extremes – summer scorchers and winter frosts – and have already learned a lot from you!
Happy to hear. Gardening is a learning process that never stops.