Don’t Let Jack Frost Steal Your Tomatoes

One of the most important tasks that you have to do in the Fall is to have a frost alert on your phone. I live in north Central Florida and I even have it on my phone.

Once the temperature dips into the 30s, you have to check the night temperature

regularly. When it gets down to the low thirties, you have to be prepared either to

protect your frost sensitive plants or harvest them before the end of the day.

Tomatoes and other warm weather vegetables, such as the nightshade and vining

vegetable, can tolerate a light frost with protection but not a killing frost. These are the plants that are planted after Memorial Day (almost guaranteed of no frost by the end of May) but there is always an exception. We had a killing frost in Mid June in Danbury, CT and all of my 30 tomato plants died.

Everything in Vegetable Gardening revolves around the last killing Frost in the Spring and the first killing Frost in the Fall. Even northern Florida gets a frost although it may

not be every year.

Frost forms at night when the air gets close to 32°F and there's a lot of moisture in the

air. The dew point is the temperature at which the air becomes so full of water vapor

that it starts to turn into liquid, like dew or frost. When these 2 indicators are close to

32⁰, the probability of frost occurring dramatically increases.

How do you know if there is going to be a frost?

You have several choices:

AccuWeather (my favorite), The Weather Channel, Weather Underground and NOAA Weather are all good apps.

Check to see if the app you have selected, allows you to set up alerts. Ask AI programs or even Alexa, or Seri if there is going to be a frost tonight.

Also ask what the air and dew temperatures are going to be. Look into the night sky. Is it cloudy or clear. A bad combination is when the air and dew temperature are very near 32⁰ and there is a clear sky. That is a very bad combination.

It's a good habit to check the air temperature and dew point every night starting one to two weeks before your area's expected fall frost date. This helps you spot when frost is likely to form. Make also sure that you have the row covers and or sheets to cover the plants.

If you are worried, then either put a double row of sheets/row covers with plastic over that or harvest the fruit. Hoops are good to keep the layers separated. Never cover the plants with anything that has plastic touching the plants.

What does frost do to vegetables growing in the garden? Well, the water vapor collects on the outside of the fruit (tomatoes, peppers, eggplant, zucchini, and other summer squashes, cucumbers, melons, etc). When the air temperature and the dew temperature are close to or below freezing, the water on produce freezes the outer layer. Any cells that are delicate, will burst open when the surface has frost on it. The fruit and foliage are ruined and has an odd translucency. The plant is now ready for the compost heap.

Other vegetables have tougher skins. These would be members of the Cabbage

Family, etc. and some even get better with a killing frost. The perfect example is

Brussels Sprouts. Their flavor gets sweater after a frost. Whether the frost damages, kills or enhances the produce, all depends on how thick the cell walls are.

Any vegetables that can be planted 2-5 weeks before the last Spring Frost will probably survive. Anything that is traditionally planted on or after the last Spring Frost will be damaged.

Now the question is how to save your produce. Frost sensitive vegetables can survive a few light frosts by putting commercial row covers or sheets over them.

Tomatoes are one of the vegetables that you can use in the green stage. Slice thickly, place a little oil on the surface and dredge them in flour and sauté. Wala! Fried Green Tomatoes!