Oklahoma Ag in the Classroom

April Page

In Oklahoma, the average date of the last frost is sometime this month.

What is the last frost date? Why does the last frost date matter?

The last frost date is the last day in spring that temperatures go below freezing. Many plants cannot withstand freezing temperatures, so gardeners and farmers must wait until all danger of frost is past before planting. Some plant earlier but provide protection (covering plants or placing a heat source near plants) when low temperatures are expected.

Common garden vegetables that are cold-sensitive include tomatoes, peppers, squash, okra and more. Cold weather garden vegetables, such as lettuce, spinach, peas, broccoli and cabbage, are not cold-sensitive and can survive light frost.

  • Have a contest, and ask students to guess what day in April will be the last frost date.
  • Set a thermometer outside your classroom so students can keep track of daytime temperatures.
  • Students use Oklahoma Mesonet or TV weather forecasts to keep track of temperatures throughout the month.
  • Discuss: Why does the last frost date matter?

USDA Plant Hardiness Zone Map

April Page

Oklahoma Ag in the Classroom

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Oklahoma Ag in the Classroom is a program of the Oklahoma Cooperative Extension Service, the Oklahoma Department of Agriculture, Food and Forestry and the Oklahoma State Department of Education.