Frost is frozen dew and it’s a plant killer. It forms when the outside temperature falls to 32 °F (0 °C) or below because the air gets too cold and the water vapor in the atmosphere freezes. Frost is tiny bits of ice that cover the lawn, flowers, garden plants, and anything else that is unprotected outdoors.
The first frost date of the year occurs in the fall/autumn. The last frost date of the year occurs in spring. Tropical climates rarely, if ever, have frost so it’s a non-issue for them. However, all other climates and growing zones being aware of the dates will help you be a more productive gardener.
Let’s take a closer look to understand exactly what the first and last frost dates are.
First Frost Date
At the end of summer when the weather begins to cool, plants stop producing, and foliage starts changing color. They know it won’t be long before the first frost arrives. The first frost can be very light and only do minimal damage to plant leaves. However, it may also be heavy and kill all the plants it lands on.
The first heavy frost of the season may be the second or third frost but it’s referred to as the first killing frost of the year.
Last Frost Date
The last frost of the year occurs in spring. It’s the time of year when winter is over but it’s still chilly outdoors. Gardeners eagerly await this time of year so they can get started with outdoor planting.
Seeds won’t germinate and tender young plants will not survive if they are planted too early and a frost falls on them. Sometimes an unpredicted late frost occurs in spring after seeds and plants have already been placed in the garden. If this occurs, a protective cover must be put over plants the night before the frost or they will be killed.
Exact Frost Dates
The exact date of the first or last frost can not be pinpointed because the local weather and topography cause considerable variations. Some calendars have the predicted first and last frost dates highlighted. Several online resources are available that can help you find the fist predicted frost date for your particular area.
The predicted dates will give you an idea of when frost will occur so you can prepare the garden and plants accordingly.