10 Ways To Help Tomatoes Survive Frost This Winter

After such a great harvest during the spring and summer months, it’s no wonder you have grown attached to your tomato plants and the product they have supplied you with.

As soon as the cooler temperatures kick in, the summer-loving tomatoes will have slowed down fruit production noticeably. The thought of them dying out during winter frost can be disheartening. 

Tomatoes favor temperatures between 65°F-80°F (18.5°C – 26.5°C).

When the temperature is regularly below 55°F (13°C), the fruit will be seen as less plump and even deformed in some cases. The fruit is still edible, but there are blemishes and scars. 

I have seen with my tomatoes that they are still flowering constantly, but they are just not warm enough to set fruit.

The morning temperatures have dropped below 10 degrees, and I am looking for ways to keep them healthy during these upcoming colder months. 

In this article, we will look at ten ways you can prolong the life of your mature tomato plants by keeping them alive for the next season. 

1. Apply Mulch

Adding mulch to the garden is always a great idea; it brings many benefits in all seasons.

Applying mulch will not only protect the surface of the soil but assists with level watering and keeping weeds away. As it breaks down over time, it will improve the soil’s drainage and add necessary nutrients.

But how can it help with frost?

A thick layer of mulch will help insulate the soil and transfer the heat to the plant. Apply a generous layer of 6 inches (15 cm) of your chosen mulch to the base of your tomato plants, leaving a space around the stalk.

After that, you can water over the top lightly. This helps the mulch to settle in.

The most common material for tomatoes is straw because of its lightweight properties and how easily it breaks down. 

Tip: Avoid applying straw to your veggie beds on a very windy day. From my experience, this results in quite a mess!

You can also use grass clippings, leaves, compost, or bark chips. These organic materials will add nutrients to the soil over time while protecting your tomato plants from the cold. 

It’s best to avoid using hay as mulch as it contains seeds, and you will forever pull out sprouted grass from your vegetable patch. 

You can head to your local garden store and see what materials you can find; some will supply a coir mulching block that you rehydrate and spread over the garden. 

2. Build A Greenhouse Or Polytunnel

Depending on your space, this is a fantastic option if you want to keep your vegetable garden alive during winter and prolong the life of your summer veggies.

Not only does it give you somewhere to keep your heat-loving plants, but it also provides you with a warm shelter to continue your favorite garden activities during the winter!

This year, I am on a mission to keep my tomatoes, peppers, and eggplants alive. I have transplanted them all into pots to keep in the polytunnel.

The morning temperature in the polytunnel is 15°C, and the tomatoes are still warm enough to ripen.  

Choosing the best polytunnel or greenhouse to suit your garden and budget is essential. There are many options available, and anything, depending on what you want to spend, will decide what you choose. 

For a budget-friendly option, you can build your own using PVC piping and nylon plastic to cover it. Some kits are available where you can buy galvanized steel and a nylon cover and install it yourself. 

The glass greenhouse will be your best option if you decide on a more significant investment. Companies available will come and build them, or you can buy a kit and install it yourself. 

When installing a greenhouse or polytunnel, some critical factors are the amount of sunlight it will receive and how much wind it is exposed to.

Ideally, you want to situate it in the sunniest area in your garden that gets the least amount of wind. 

I am experiencing strong winds in my area; some winters reach 60 km, and the polytunnel plastic soon gets shredded. If you are in a windy area, try to install some wind brakes to protect it more.

3. Grow Tomato Species For Cold Climates

Some tomatoes are happy in cooler climates, and some can set fruit at 3°C!

Predictably seasonal temperatures are the past, with the weather changing so much these days. If you are a dedicated gardener, these drastic changes in temperatures can bring about some negative surprises.

It requires a bit of forward-thinking, but if you want to keep your tomatoes flourishing through the cold winter months, you can have a look at these species to start growing:

  • Siberia – Available during summer and fall, a dwarf, a low-growing plant known to produce around 30 egg-shaped tomatoes on one bush. Ability to set fruit at 38°F. It takes 50 days to mature. 
  • Celebrity – Naturally resistant to common diseases, drought-tolerant, and grow in a bush from up to 4 feet. It takes 60 to 70 days to reach maturity and produces medium-sized fruit up to 10 ounces.
  • Golden Nugget – Cherry-sized fruit, resistant to some diseases, takes 60 days to mature, Determinate growing habit. It still requires protection from under 44°F (7°C).
  • Orange Pixie – 4-ounce pumpkin-shaped fruit that can grow up to 120 cm high; dwarf varieties available. 52 days to maturity, disease-resistant, and tolerant to 50°F (10°C).
  • Oregon Spring -Large red, nearly seedless fruit will grow up to 2 feet high. Will reach maturity in 65 to 70 days. Seeds germinate at 50°F (10°C), and seedlings can be planted when it is consistently 45°F (7°C) at night. 

As you can see, a range of tomatoes is available to grow through the cold season, and you can choose a selection or just one type for your garden.

4. Outdoor Decorative Lights

These are mostly recognized as Christmas party decorations. Still, you now have another use for those lights you put away each year.

A great way to give subtle heat to your tomato plants is to use some fairy or outdoor decorative lights.

The incandescent lights we hang around the Christmas tree each year give off a small amount of heat, making them ideal to use by your plants during frost time.

The LED version doesn’t give any heat, so it’s essential to ensure you use the correct bulb.

To use the lights during the frosty months, lay them around the ground next to the plant or clip them to the stakes you have used to support the plants. 

Ensure the bulbs are not touching any of the plant’s foliage, and you can drape a lightweight blanket over the top at night to trap the heat. 

You can expect an increase in temperature with this method of around 2°F-10°F (1°C-7°C).

5. Plastic Tarpaulin

To avoid the disappointment of losing your heart-loving tomatoes during the cold months, you can use a clear plastic tarp or sheet to protect them.

Most of your local garden and hardware stores will be able to supply you with the right meterage you need to cover your plants. 

When choosing suitable plastic for your plants, ensure that it’s not too heavy, as this may cause damage. 

To use a plastic tarp to protect your tomatoes, you must create a small guard around each plant. You can do this with 3 or 4 bamboo or metal stakes that are taller than the height of the tomato plant. 

Once your stakes are in place, cut the right size of plastic required to cover the plant. Essentially you are creating a plastic tent for your plants; you can clip the plastic sheet to the stakes using some plastic stake clips. 

It is vital to ensure that the plastic doesn’t come into contact with the plant. Plastic touching any of the foliage during the frost will cause the plant to freeze and damage the leaves. 

After the morning frost has melted, you can remove the plastic, let the plant breathe, and enjoy the sunshine again. 

This method is excellent for short-term frosts, and as the frosty months are approaching, you can leave the stakes in place and fit the plastic cover when needed. 

6. Small Hoop House

Many gardeners will discard the winter months in their gardens, as they are deemed non-productive when there is a lot you can do with a winter garden. 

If you are watching the forecast and seeing that the frosty days are coming, preparing your garden for the next stage of the year is a great idea.

Having some introductory materials on hand will help you protect your new seedlings and frost-sensitive plants. 

Tiny hoop houses are a great option if you need more space for a full-sized polytunnel.

They are flexible with where you can build them, meaning anywhere in the vegetable bed where you need to shelter the plants is where you can place them. 

To create a small hoop house over your plants, you will need:

  • PVC Polypipe, with 8 ft length
  • Metal stakes
  • Nylon sheeting or bubble wrap
  • Pole clips to secure the plastic to the PVC Polypipe

To start with, hammer in the metal stakes around the edge of your vegetable bed approximately 4 feet apart. These are going to provide support for the PVC pipes to attach to. 

After the metal stakes are securely in place, you can take your PVC pipes, secure each end to the metal stakes, and bend them over the top of the plants. This will create a hoop to hold the plastic sheet above the plants. 

Once the hoops are in place, take the nylon sheet or bubble wrap and drape it over the top of the rounds. You can use pole clips to keep the plastic in place.

You want to ensure the plastic is tightly wrapped over the hoops to prevent it from flapping in the wind. 

The bubble wrap is excellent to use as each little bubble holds warm air that will provide insulation for the plants. It may not look the best, but any additional help is always good. 

This method is something I will be concentrating on in the coming months, not only to provide shelter from frost but to keep the hoops in place for the summer.

That way, I can drape a light shade of cloth over them to protect them against the blazing hot summer sun.  

7. Season Starters 

These are sometimes referred to as water wall protection and do precisely what they say.

A double layer of plastic is filled with water in the middle to hold the heat from the sun and prevent frost from hitting the plants. The layer of plastic creates the greenhouse effect and is fitted around the plant. 

There are plenty of options available on the market with ready-made Season Starters. Still, you can easily make your own at home from recycled plastic bottles.

To make your Season Starters, begin by taking around seven 2-liter soda bottles and washing and removing the labels. This should be enough to enclose a small plant. 

Gently remove a ring of soil 1 inch deep around the base of the plant for the soda bottles to stand in. Fill each bottle with water and place them standing up in a ring around the plant. 

Ensure there are no significant gaps between the bottles, as you want to avoid any cold air entering.

If you are adding a wall of water around newly planted seedlings, ensure you can add extra bottles to the ring as the plant grows.

This is an excellent method to protect small plants from harsh conditions. If you need to protect taller plants, I suggest looking at another approach.

Soda bottles are pretty limited in height, so measure the plant beforehand to see if it will sit behind the bottle. 

8. Garden Domes

Garden domes are one of my favorite methods for protecting plants. They reduce landfill and give use to those plastic bottles we buy each week.

Garden domes, sometimes known as cloches, have been used by gardeners for many years. When you see them in a garden, they often spark curiosity about what is inside.

My grandad used to put them in the garden, and when I was a child, I couldn’t help lifting them to have a sneak peek!

They protect seedlings from frost and are often used at the beginning of the season to create a humid and warm environment for seedlings. 

This simple and effective method protects young plants from extreme and unexpected conditions.

The size of your plant will determine whether you can use this method to protect them. For example, if your tomato plant has grown to 4 feet, it is improbable that you will find a plastic bottle or jar to fit over the top.

You can often reuse plastic water bottles and cut the bottom off to create the mini greenhouse effect, or you can buy or use glass jars turned upside down.

If you want to go one step further to add warmth to your plants, you can wrap the plastic bottle or jar in bubble wrap to add another layer of insulation. 

9. Water In The Afternoon

Having a regular watering routine is essential for your tomato plants’ health. Still, the time of day you give your tomato plants water matters too. 

There is a common debate among gardeners about what time is the most suitable to water your garden. The evenings are not an option for me, so I wake up early in the morning to give my veggie patch a drink. 

As the forecast changes towards the end of the year and frosts are due, changing your watering time to the afternoon to protect the plants is recommended. 

Watering tomato plants when the sun is at its highest will help retain heat in the soil; as the night comes, the heat from the soil is diffused to the plant and will prevent frost.

When watering during the day, ensure you are watering at the base of the plant and no water hits the foliage. The sun is still warm and can damage the leaves if they hold water on the surface. 

10. Water Jugs

Like the wall of water method, using clear sealed jugs of water next to your tomato plants will hold heat around that area. That’s similar to the hot water bottles we use in bed on a cold winter night. 

This is a priceless solution if you are strapped for time before the frost arrives. It only costs you the price of water, and you can use it the next day to water the plants. 

To use water jugs or buckets as a frost protector for your tomato plant, take several jugs or clear containers and fill them with warm water. Place them around your tomato plants and leave them to heat up in the warm afternoon sun. 

They will keep the heat through the night. The water jugs and a plastic sheet over the top will ensure your tomatoes have enough heat to beat the frost. 

Ensure the jugs of water are not touching the plants, as you want to avoid any damage to the leaves. 

To Sum Things Up

There is no need to panic about the cold season and your tomato plants if you live in an area with regular seasons. Some solutions to keeping your tomatoes alive during the frost; most are temporary and require a little cost. 

The most important duty of a gardener enduring winter temperatures is to be prepared and think ahead. 

Keep a lookout for the local temperature forecasts and install what you need to keep your plants happy.