First and last frost dates (and why they matter)

Ask any successful gardener their secret, and they’ll probably mention two dates: first and last frost. These dates tell you when it’s safe to plant and when you need to protect what you’ve already grown. Miss them and you’ll be replanting everything.

If you’re a budding gardener and want to know more about keeping your plants healthy during the winter, keep reading, as we’ll explain everything you need to know about frost dates across the UK. You’ll learn what these dates actually mean for your patch, which plants are most vulnerable to frost, and how to find the exact dates for your location. Plus, we’ll share some practical tips to protect your plants from cold damage.

What is a frost date in gardening?

In gardening, frost dates refer to the times of year when temperatures drop low enough to freeze water on plant surfaces. When this happens, the ice crystals can damage or kill plant tissues, particularly new growth and flowers. Gardeners track two main frost dates: the first frost of autumn and the last frost of spring.

The most important date for most gardeners is the last frost date in spring. This tells you roughly when winter’s final cold snap will occur, so you know when it’s safe to plant tender vegetables like tomatoes, peppers, and beans. Plant before this date and you risk losing everything overnight.

However, note that frost dates change based on your area. As part of good garden maintenance, professionals often wait a week or two after the average last frost date before planting delicate crops, giving themselves a safety buffer against surprise late frosts.

What is the first and last frost date?

The last frost date refers to the final spring frost in your location, while the first frost date marks the beginning of autumn frost. These dates and temperatures vary greatly depending on your region and elevation. Urban areas heat up quicker in spring than rural locations, which can shift last frost dates by several days or even a week.

Whether you’re protecting plants with mulch in autumn or planning a spring garden, understanding your local frost patterns is crucial. The following table shows the approximate range of last frost dates across the UK.

By getting the timing right, your initial plantings will be protected from cold temperatures, ensuring they have the best chance to not only survive but thrive.

Vegetables standing strong against winter chill. (Source: iStock)

How does the last frost affect vegetables?

The last frost can kill vegetables already growing in your garden or damage crops you’re trying to harvest. Vegetables like tomatoes, peppers, and butternut squash still on the vine will be destroyed if exposed to freezing temperatures. During this time, their fruits turn mushy and inedible, and any remaining flowers or young fruit are lost. 

Hardy vegetables like kale, carrots, and Brussels sprouts actually benefit from the last frost of spring or the first frost of autumn. The cold exposure converts starches to sugars, making them taste sweeter. Meanwhile, crops like lettuce and spinach can survive the last frost but may show some leaf damage, though the inner leaves usually remain perfectly edible. 

Some fruit trees, like apples and pears, can benefit from frost winters, too. They are hardy trees that require enough exposure to cold temperatures or ‘chill hours’ to prepare for the growing season. Having enough chill hours is essential for fruit trees like these because this helps prevent them from staying dormant after winter, allowing them to grow healthier and produce sweeter fruits in spring. 

Rhubarb is another excellent example of a plant that can benefit from the frost. Often mistaken as a fruit, rhubarb is a vegetable that needs to be exposed to at least 500 hours below 49 degrees Fahrenheit to ensure it comes out of dormancy after the winter, helping it grow healthily once the spring season begins. 

How do you find your specific last frost date?

Understanding first and last frost dates is much easier for gardeners today, thanks to the many online resources available. For example, Plant Maps offers the easiest way to understand your UK region’s average annual temperatures. The Met Office also provides historical weather data to help determine frost risk in your area.

Frost dates are based on historical averages, meaning unexpected frosts can still occur. To protect your plants, allow a little buffer time and keep an eye on the weather forecast.

Frosty mornings challenge young plants. (Source: iStock)

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

There are many online resources that will help you understand the first and last frost dates for your area. The National Weather Service and the Met Office often track 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?

Some plants are very sensitive to frost and may need extra protection. These include:

Fruits & Vegetables

• Avocados

• Citrus trees

• Tomatoes

• Pumpkins

• Sweet potatoes

• Cucumbers

• Okra

• Eggplant

• Corn

• Peppers

Plants & Flowers

• Fuchsia

• Bougainvillaea

• Begonias

• Impatiens

• Geraniums

• Succulents

• Tropical plants

If you plan on growing any of these, be sure to check your local last frost date to avoid damage.

Which crops and plants can withstand frost?

The UK climate allows for a variety of frost-hardy fruits, vegetables, and plants. These hardy varieties can extend your growing season and ensure a successful harvest even in colder months.

Fruits & Vegetables

• Carrots

• Broccoli

• Peas

• Brussels sprouts

• Rhubarb

• Apples

• Pears

• Onions

• Leeks

• Black currants

Plants

• Heather

• Holly

• Yew

• Ivy

How can I protect my plants from frost?

Home gardeners can protect their plants from frost in several ways. Some of these techniques involve mulching, pruning, temporary greenhouses, and watering plants in the morning.  

• Mulching: Organic mulch like straw or bark helps insulate the soil and retain warmth, protecting roots from frost.

• Pruning: Removing frost-damaged leaves or branches through pruning can help prevent dieback in plants. It can also help stimulate plant growth, allowing it to grow new shoots, branches, and roots instead of distributing their stored energy to the damaged parts.

• Frost covers or mini-greenhouses: Use horticultural fleece, cloches, or even old bedsheets as protective covers. Remove them during the day to allow airflow.

• Watering plants in the morning: Moist soil retains heat better, so watering before a frost can help keep roots warm.

• Using plastic bottles or containers: Covering small plants with plastic bottles can create a mini greenhouse effect, trapping warmth and shielding delicate leaves.

Get your garden timing spot on

Armed with your local frost dates, you’ll never have to guess when to plant again. However, knowing when to act and actually getting the work done are two different things. 

If you need help with frost protection, seasonal planting, or general garden maintenance, Airtasker gardening experts are just a click away. From general yard work to other outdoor areas that need attention like pool maintenance, there’s always an expert ready to lend a hand.