How do I know when the first frost or last frost will be?

Knowing when the last frost is expected in spring is best left to the experts. You can determine your garden’s first frost by checking a thermometer to see if the temperature has dropped below 32 degrees and visibly seeing a layer of frost on your plants and the ground. However, this is not necessarily helpful to you, because, as a gardener, you probably were trying to get something in the ground before the first frost occurred.

The easiest thing to do is look up the first and last frost date estimates published by your local extension office or go to a site like The Old Farmer’s Almanac where you can enter your ZIP code and find out the estimated first and last frost dates for your area.