Protecting Tomatoes from Frost and Freezing

Since 2010, Tomato Dirt has garnered 4.6+ million views, making it the web’s leading online source for growing tomatoes in the home garden. Award-winning writer and Tomato Dirt owner Kathy Widenhouse has helped thousands of home gardeners grow healthier tomatoes. Be one of them when you get Tomato Dirt’s Growing Guide here.

Cold temperatures can damage or destroy your tomato plants. Protecting tomatoes from frost and freezing is important to having healthy crop – both at the beginning of the season and at the end.

The most important step to protecting tomatoes

The best step you can take to protect tomato plants from frost is to pay attention to the weather forecast. When you hear a frost or freeze warning, take appropriate steps to protect your plants.

What’s the difference between a freeze and a frost?

Protecting tomatoes from frost and freezing with Tomato Dirt. Helpful tomato growing tips.

A freeze occurs when the temperature dips below 32ºF (0ºC). Usually a freeze affects an entire region and may last several days.

Temperatures associated with a freeze are lower than temperatures associated with a frost.

Surprisingly, tomatoes can survive a light freeze if it is not accompanied by frost, provided temperatures don’t dip below 28-30ºF.

A frost, on the other hand, is localized. Low temperatures may or may not reach freezing, but moisture must be in the picture for frost to develop. 

A frost typically falls overnight but during the following day, temperatures warm. Tomato plants cannot survive frost.

How does frost develop?

Certain conditions allow frost to develop.

1. First are clear skies and calm winds, which allow crystalsr to accumulate.

2. Heat radiates from the soil, leading surfaces to get colder.

3. Moisture comes into contact with soil and plant surfaces.

4. Moisture crystallizes on the tomato plant, destroying the plant cells when it melts. When damage is severe, the plant dies.

What is “black frost”?

In very dry, cold weather, it’s temperatures (not frost) that can damage plants. Cold temps darken leaves and stems. That’s why the condition is called “black frost.”

What to know about protecting tomatoes in a frost

  • Frost can occur when temperatures are as high as 40ºF. Moisture, rather than temperature, is the determining factor.
  • Low-lying areas, where cold air settles, are more susceptible to frost. If your tomato patch is in a low area, pay special attention as temperature dip into the 40s.
  • Tomatoes cannot withstand frost. When a frost warning is forecast for your area, choose from various types of frost protection to safeguard young plants in the spring and mature plants in the fall. Tunnel row covers, water barriers, individual plant covers – even sheets, blankets, and plastic – can help save tomato plants from frost injury. (Find out more about different types of frost protection). 

More on protecting tomatoes

Protecting plants from frost: FAQs ...

Planting tomatoes: how to help your crop succeed ...

13 Easy Ways to Protect Plants from Frost ...

How to harden off tomato plants to prepare them for the garden ...

 Different types of frost protection for tomato plants ...

How to use individual frost covers to protect tomatoes ...

Floating row covers and tunnel row covers for protecting tomatoes ...

How to protect tomatoes on cold nights ...

More tips for protecting tomatoes on our Pinterest board ...

More on ripening and harvesting tomatoes

Harvesting tomatoes: when to pick them ...

Ripening green tomatoes to extend your harvest ...

10 tips for ripening tomatoes on the vine ...

How to extend the harvest of homegrown tomatoes ...

When are my tomatoes ready to pick?

Kinds of frost protection for tomato plants ...

Return from Protecting Tomatoes to Tomato Dirt home

As an Amazon Associate and Rakuten Advertising affiliate I earn from qualifying purchases.

New! Comments

Have your say about what you just read! Leave a comment in the box below.

SHARE THIS PAGE:

 

FREE! 10 Must-Know Tomato Growing Tips: 20-page guide
Get yours here: