It’s always a bit sad when you’ve just planted out some new bulbs or vegetables, and a late frost wipes them out. So what kinds of plants can survive a frost and at what temperature, so we can plant accordingly?
Many but the most delicate plants can survive a light freeze of 29° to 32° Fahrenheit, but more plants will be harmed by a moderate freeze of 25° to 28° Fahrenheit. However, when it comes to a hard freeze of 25° Fahrenheit and below then most plants will be killed.
Let’s have a look at what types of plants, flowers and vegetables can survive freezing temperatures of varying degrees of severity…
At What Temperature Does Frost Kill Plants?
Some plants are better able to withstand cold temperatures than others. Many plants will cope with a light freeze; however, most plants won’t survive a severe frost.
Let’s break this down into different categories of freeze.
- A light freeze. This is around 29° to 32° Fahrenheit. Tender plants will not survive this slight dip below freezing.
- A moderate freeze. This is a few degrees lower at 25° to 28° Fahrenheit. This is cold enough to harm many types of plant.
- A severe freeze. Also known as a hard freeze, this plummets to 25° Fahrenheit and below. Most plants will be destroyed by a severe frost.
When you’re choosing frost-hardy plants, check out this handy guide to the US planting zones.This gives you a state by state guide to the growing conditions across the US, and gives the average temperatures across the area.
You may have also seen “Hardiness Zone” written on plant care instructions. This is a US-wide system that uses a scale to match plants with suitable growing zones. Zone 1 is suitable for super-tough plants that can survive a deep freeze. The scale goes up to Zone 13, which is tropical plants.
In this article, we’ll be looking at plants that can survive and even thrive at the lower end of the hardiness scale. We’ll help to get you started with a guide to frost-hardy plants.
What Plants, Flowers & Vegetables Can Survive a Freeze?
You’ll be surprised by how many different types of shrubs, flowers and vegetables can survive freezing temperatures. They may need a little attention from you to make it through the winter, but they will reward you tenfold with beautiful spring blooms or tasty winter food.
We’ll start with ornamental plants like flowers and shrubs. Naturally, blooms like snowdrops and winter aconite are great in cold weather, and flowers that grow from cozily buried bulbs (like hyacinths) will do fine.
However, there are far more frost-hardy plants than you might suspect. Don’t judge a book by its cover when it comes to frost-hardy plants: sometimes, the most delicate-looking varieties can be extra-tough in cold temperatures.
Peonies
Peonies will survive a frosty spell, and go on to produce the most beautiful fragrant blossoms in the late spring and early summer. They actually need a bit of colder weather to create their gorgeous blooms.
Lily Of The Valley
These bell-shaped blooms look so delicate, but can survive a moderate frost. It’s not fussy about soil and can be grown in the shade. It’s an excellent choice if you like dainty flowers but live in one of the frostier zones.
Siberian Iris
The clue’s in the name, right? These low-maintenance flowers will thrive in Zone 3 and don’t mind either wet or dry soil. They bloom in the spring and early summer, and are the most beautiful shade of blue.
Pansies
Pansies are a well-known way to bring color to your yard in the winter. They’re not as tough as some of the hardy plants here, but will survive a cold snap and will happily bloom all through a milder winter.
Candy Stripe Flox
These beautiful and distinctive striped blooms can even be grown in Zone 3 gardens. It blossoms in the spring, and because it’s evergreen, keeps your yard looking well-stocked all year round.
Sedum
Can’t grow succulents in a cold climate? Think again. Pretty sedum is astonishingly hardy, and can even survive in a Zone 3 yard.
Evergreens
These lovely trees and shrubs are known for their rich, winter foliage, and we’ve all seen pictures of evergreen branches draped in snow. So yes, most evergreens will survive cold weather! However, you still need to look after them. Apply a layer of mulch during the winter, and make sure that the frozen ground doesn’t cause the plants to dry out.
What about vegetables? It’s mostly good news for vegetable growers, as many plants grown for food are frost-hardy, and some will even survive even a severe frost. Here are a few of our favorite vegetables that are happy in a cold climate.
Carrots
Carrots can survive in frosts that go right down to 20°. Don’t worry if their leaves look damaged as the roots are safe underground. Help them survive by adding a generous mulch of something like hay. This has the added bonus of preventing the soil from freezing, so you can continue to harvest your crop.
Turnips
Exactly the same as carrots. These super-tough vegetables will stay safe underground even during a hard freeze, and will keep growing in between freezes. Again, add a good layer of mulch at ground level.
Brassicas
Some members of the brassica family (such as kale, broccoli, and cabbage) do very well in cold climates, and can survive temperatures down to 20°. Good news if you live in Alaska: some brassica cultivars have been successfully grown in the Arctic Circle.
Potatoes
Potatoes are a “semi-hardy” crop. They’ll survive a lighter frost but not a severe freeze. Don’t panic if the leaves look harmed, as the potatoes underground will cope with a touch of frost. Currently, scientists from the US and Peru are working to develop a frost-hardy potato cultivar.
Parsnips
Like potatoes, parsnips are fine in the higher bracket of freezing temperatures. Actually, they’re one of these strange crops that do better if exposed to a light frost. Their flavor is better if they’re grown in freezing conditions.
Spinach
Again, spinach will survive a light frost, but not a heavy one. Give it a good mulching so it survives the winter and becomes a much-welcome spring crop.
Radishes
The fall is actually the best time to plant your radishes, and you can harvest them in the colder months. They actually don’t like heat, so make an ideal winter crop. Try the Japanese Winter Radish, Daikon. These naturally like colder climates, although look quite different to typical radishes, being long and white.
Apples
Let’s leave vegetables and take a quick look at fruit. Apple trees are pretty tough, and a winter frost doesn’t affect them. In fact, cold helps them set the fruit for later growth. The problem happens if they’re hit by a late frost in the spring, which can cause damage during flowering. The resulting fruit will have “frost rings”. These apples are still edible, but aren’t as pretty.
If you have a fruit tree, consider protecting it during a spring frost. You can use something like an old bed sheet, which you drape over the tree at night during cold spells. We’ll take a closer look at protecting plants from frost in just a moment.
How Do I Protect My Plants From Frost?
There are several ways to protect your plants from frost. It’s really worth taking a bit of time to make some of these steps, to ensure that your plants, flowers and crops survive the colder weather.
We’ve already mentioned mulching. A good layer of something like hay, wood chips, or leaf mulch will warm up the soil. Aim for at least 2 inches, 4 if you can.
Cover the plants with a fleece. You can buy these at garden centers and home stores, and fleeces come in different sizes and frost ratings. Just make sure they’re firmly secured…
Or, try a DIY solution like a tarp, a drop cloth or burlap. Again, secure them, and make sure they’re not squishing the plants. Remove them during the day, and then tuck the plants in again at bedtime.
You use a temporary cover like a cloche or a cold frame during the winter. This is a small-scale version of a greenhouse, and you can easily make your own in which to winterize your plants. For example, any clear plastic dome will make a decent cloche.
Bring them indoors. Grow your less-hardy plants in containers and simply bring them inside during colder weather.
Choose the right planting places. Put the less-tolerant plants close to the wall and in sheltered, sunny spots. Which bits of your yard get the least frost? That’s where the more tender plants need to go,
And of course, think before you buy! There’s no point attempting to nurture succulents outdoors if you live in a Zone 3 climate. If your zone is prone to freezes, look out for hardier varieties. Also, keep an eye on timescales. An annual summer-blooming plant or fall-harvested vegetable may never have to see a frost.
Conclusion
Depending on whether the frost is light, moderate or severe – various plants can actually thrive at different levels of lower temperatures.
However, if the freeze is particularly hard – below 25° Fahrenheit – then your plants may go to heaven no matter what type and variety they are.
The best thing to do if you’re in doubt, or don’t want to get caught by a late season frost – is to protect your plants, flowers and veggies using the methods above.
With all the hard work you’ve put in it’s better to be safe than sorry. 🙂
