First and last frost dates (and why they matter)

The first frost dates and the last frost dates should be in any gardener's calendar. Understanding these as part of your garden timing will help you avoid frost damage to your plants and flowers in the spring weather.

The first signs of Spring can be difficult to navigate for many gardeners who are starting their seed plan. A great way to avoid any issues and prepare for this is by understanding when to plant.

In many cases, this means getting plants in the ground when the average last frost date passes. This will change based on your area but is a crucial first step to ensure you enjoy a successful spring garden.

What is the last frost date in gardening?

A frost date refers to temperatures that fall to 32°F or lower, which is cold enough to damage or kill your plants. Understanding these timelines will let you know when the optimal growing season will be. The last frost date in Spring signifies the end of the cold snap and a good time to start your new garden.

Read on to understand more about frost dates and why they are important.

What is the first and last frost date?

The last frost date references the final spring frost. The date and temperature will vary greatly depending on your state and elevation. Whether you’re in an urban or rural environment also plays a role. Urban areas heat up quickly in Spring, and as a result, the last frost dates can change by a few days or even a week. 

You can quickly look up which zone your state falls under from this Plant Hardiness Zone Map from the  U.S. Department of Agriculture.

By getting the timing right, your initial plantings will be protected from cold temperatures, ensuring they have the best chance to survive.

How does the last frost affect vegetables?

The last frost date in Spring essentially determines when the first seeds of your new plantings will germinate. During Spring, the nights reach temperatures too cold for new vegetable plants to survive in.

Spring crops like lettuce, carrots, cabbage, spinach, and radishes may be able to withstand colder temperatures.  However, warmer-season crops, like cucumbers, tomatoes, and butternut squash or pumpkin, will struggle. 

💡 Pro tip: Most seed packets will reference planting guidelines based on the last frost date. By understanding more about your climate, you can plan with this information or work with a gardener who can help you.

How do you find your specific last frost date?

Thanks to the many online resources available, understanding first and last frost dates is easy. For example, the abovementioned Zone Map from the USDA is the easiest way to understand the average annual temperatures in your region. 

It is important to note that the last frost date data is based on historically averaged temperatures. As a result, there is a slight chance that frost can occur after the dates listed, creating frost damage on plants. We recommend building in a little buffer to allow for this if you are worried about plant damage.

Always keep an eye on the weather forecast as well. Seed guidelines are available to work from your last frost date, and with the right timing, you'll enjoy a bountiful spring garden!

How do you know when it's the last frost?

Many online resources will help you understand your area's first and last frost dates. The National Weather Service often tracks this data as well. It is important to know that no matter where this information comes from, there can be a slight variation in the actual date due to changing and unpredictable weather patterns.

What plants are sensitive to frost?

A range of tender plants and edibles can be susceptible to frost. This may include:

Fruits & Vegetables

• Avocados

• Citrus trees

• Tomatoes

• Pumpkins

• Sweet potatoes

• Cucumber

• Eggplant

• Corn

Plants & Flowers

• Fuchsia

• Begonias

• Impatiens

• Geraniums 

• Succulents

• Tropical plants

If you are planning on planting any of these, be sure to find out when the last frost dates are in your area, so you can ensure their survival by planting afterward.

☞ Learn more: Gardening basics

Making sure you have a happy garden

There are many different things to be aware of to ensure your garden thrives; it's one of the reasons why we have the gardening hub, a place for helpful resources to help you have the greenest of thumbs.

If you need an extra hand in the garden, plenty of Airtasker gardening experts can offer their services. From general yard work to other outdoor areas that need attention like pool maintenance, there is always a Tasker ready and willing to help.