Unless you are enjoying life in a tropical paradise, most people have to watch out for the frosts of winter every year. For many plants, frost is a killer and you should be planning out your entire season around the 2 frost dates. The dates are based on historical averages, so don’t consider them 100% guaranteed by any means.
First, there is the date of last frost in the spring. Many folks consider this the starting point for the growing season even though many plants can be planted (or started indoors) before this date. Once the threat of frost is passed, anything can be planted outside safely.
Then you have your first frost date in late fall, roughly marking the end of your growing season. You should keep a close eye on this one, but it’s the immediate forecast that matters. If you have some end-of-the-season plants still out in the garden, and they’re calling for freezing temperatures, then you’ll want to get things picked and harvested right away. On the other hand, if the date has arrived and the forecast is still warm and balmy, just enjoy it and let your plants have a few more days to grow.
If you have vulnerable plants out there and an unexpected frost is predicted, don’t despair. A light covering of cloth or plastic can do wonders in protecting your plants if you don’t have time to get out there and pick. Also, a frost can be followed by a week or more of frost-free weather. It would be a shame to yank all your plants before necessary.
You can find out your local frost dates by checking with the extension office for your area, or finding a website online with maps.
Why is frost such a problem? Once the temperature drops below freezing at night, the water will freeze in the tissues of your plants. Ice crystals form which then burst the little plant cells, causing all kinds of damage. Some plants can withstand a little frost, some will turn to dead green mush after one single frosty night. Get to know which of your plants handle frost so you don’t panic in the cold.