Fall is fully underway now, and winter is looming around the corner. In those days between the two seasons, you might see the occasional frost advisory or freeze warning. But are they the same thing?
As it turns out, a frost and a freeze are different. It’s all about temperature (but you probably figured that one out already).
Frost and freeze alerts might not matter much to the average person (other than knowing to grab a jacket), but if you’ve got a garden or any outdoor plants, the alerts are particularly important as the weather could significantly damage your plant babies.
For most gardeners, a frost advisory isn’t a huge cause for concern. It means that temperatures will fall between 33-36 degrees Fahrenheit. For those temperatures to affect the Earth and kill a plant, the soil will need to lose enough heat to make the ground freeze. During a frost, it doesn’t quite get there. Instead, the tops of plants will likely be frosted and killed off, but the lower portions are just fine.
The 2023 Old Farmer's Almanac
Grab an Old Farmer's Almanac to keep track of frost dates.
A freeze warning is when you should be concerned. With these alerts, temperatures will fall to 32 degrees Fahrenheit or lower. When this happens, plants’ interiors actually freeze, and when they warm back up during the day, they release water. The plant then begins to break down resulting in mushy areas and likely death.
When you get a frost or freeze warning, it’s important to protect your plants. Use winter mulch or a tarp to keep the ground warm, and be sure you know your plant hardiness zone so you can anticipate when these events might occur.