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Can I Cover Plants With Garbage Bags to Protect Them From Frost?

Winter can be a tricky time for gardening – especially when the frosty weather takes you unawares!

Many plants will not survive exposure to cold weather, so what is the best way to keep our treasured plants warm and safe?

We’re about to share our favorite methods to keep your garden safe during overnight frost.

We’ll also share our tips on how to protect your plants using trash bags.

Sound good?

Let’s begin!

Can I Cover Plants With Garbage Bags?

Covering your crops and plants with trash bags can protect them from frost. But cover your plants thoroughly so that heat cannot escape! Also – use stakes to prevent the plastic from touching the plants. Other suitable materials to protect against low temperatures and frost damage at night include fabric sheets, frost blankets, and a thick layer of mulch.

What Happens When You Cover a Plant With a Plastic Bag?

preparing for winter with plant cover
Cloth, polyester, or plastic bag plant covers do a great job of preventing frost and protecting your plants. Make sure the plant cover reaches the ground! The plant covers work by capturing and retaining heat.

Our garden plants are living things that need the correct environmental conditions to survive. So, while covering your plants with garbage bags might seem like a good idea, there are some issues that you need to consider.

The first problem with plastic is that it does not have good insulating properties. It could raise the temperature by a couple of degrees and protect from a light frost. But – it will be ineffective in temperatures substantially below freezing.

This problem is even worse if the plastic touches the leaves. You might find that the two become frozen together!

For this reason, you must use stakes and hoops to create a plastic canopy over the plants – rather than draping the plastic onto the leaves.

Plants also need moisture, sunlight, air, and the right temperature conditions to thrive! So, your plastic garbage bag might keep everything warm and snuggly at night. But during the day, the bag creates a warm, dark, and humid environment.

The point is to avoid smothering your plants under the sun. They need plenty of oxygen – and you don’t want to strain them.

You should remove the garbage bag from the plant as soon as the sun starts to warm the air in the morning. Replace the plastic bag again at night if the threat of frost persists.

Read More – The 7 Best Plant Covers for Winter Crops and Winter Frost!

How Do I Protect My Plants From Spring Freeze?

portable garden bed inside wagon with frost cover
We love this raised garden bed on a wagon! Now you can tuck your wagon into your shed or garage when a heavy frost or snow comes along. Notice the protective cover on the wagon, too. Perfect!

Springtime is a delicate balancing act for us gardeners! While we want the warm spring days to encourage our seeds to sprout and plants to grow, the cold nights can still bring the risk of frost.

There are several methods you can use to help plants thrive through the winter and into the spring:

Choose Low-Growing Plants

Mulch low-growing plants in the autumn. A thick layer of mulch will retain water and heat, giving your plants the best chance of survival.

Provide Plant Cover

Use cloches, cold frames, and garden fleece to help increase the temperature of your plants. You would be amazed at what can work to keep plants warm – my favorite piece of garden equipment is a cold frame propagator we constructed using old windows!

Our Pick
Valibe Plant Covers Freeze Protection Floating Row Cover Fabric
$28.99 $17.99

These blanket plant covers protect from frost and offer 10-feet by 30-feet of coverage. Perfect for surprise frosts, pests, and also protecting crops that don't want direct sunlight.

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We may earn a commission if you make a purchase, at no additional cost to you.
08/11/2022 02:34 am GMT

Plant at the Right Time

Sow plants at the right time. The timing might sound obvious! But, many of us get itchy sowing fingers in the spring! Starting frost-sensitive plants too early often results in every windowsill in the house covered in leggy seedlings, waiting for the risk of frost to pass.

Protect From Overnight Frosts

Cover larger plants overnight with insulating materials to make the warmest possible conditions. We are nurturing some young avocado trees through a frosty winter with the help of mulch around the roots, cardboard around the trunk, and an insulated canopy over the top. Fingers crossed that these sensitive guys make it through to spring!

Bring Small Plants Indoors

Bring pots and containers inside for the winter. You can move them into a polytunnel or greenhouse. Or even a dark shed if the plants are dormant.

So, if you have frost-sensitive plants, some careful planning can help to nurture them through the winter.

The time and effort put in will reward you with healthy, thriving plants with high yields.

It is well worth taking the time to look around your garden and see which of your beloved plants might benefit from some snuggly winter clothing!

Read More – How to Protect Tomato Plants During Winter?

Winter Crop Cover FAQs

winter raised garden bed with frost cover polytunnel
I’ve salvaged plenty of crops by using makeshift polytunnels and hoop-houses! Polytunnels don’t work miracles – but can protect you from a surprise frost if you transplant your cold-hardy veggies early. Or late!

We know that it can be tricky to decide on the best method of protecting your plants, so we have all the answers you need right here!

Will Covering Plants With Plastic Protect From Frost?

Covering plants with plastic will give some frost protection, but the plastic mustn’t touch the plants or the leaves. Protecting your plant from frost means that you need to use stakes or canes to form a structure over the plant to support the plastic. In effect, you are making a mini greenhouse or polytunnel to keep your plants warm!

At What Temperature Should I Cover My Plants?

Timing is everything if you want your plant cover to save your garden! Use your plant cover whenever the temperature threatens to come close to freezing. Remember that the forecast is not always accurate, so it is best to err on the safe side here.

The most sensitive plants (like tomatoes) get severely damaged by temperatures of 32 degrees and colder. Some hardier plants, such as spinach and chard, will survive a mild frost but be killed by temperatures below 28 degrees.

What Can I Cover My Plants With Safely?

Light blankets, cloth, and frost sheets work wonders. If you are worried about the risk of frost damage to your plants, then it can be a good idea to cover them overnight. The best cover material will raise the air temperature around the plants by several degrees, giving them a much higher chance of survival.

The good news is that you may be able to cover your plants with materials you have lying around the place or reuse something intended for another purpose.

Can You Use Garbage Bags to Cover Plants?

Yes – if you secure the plant properly. Garbage bags work to cover plants and protect from frost, but they must not be allowed to touch the plant’s surface. Use stakes and supports to create a tent-like structure over the plant, which will retain warm air. Make sure the trash bag goes all the way to the ground.

Remove the bags during the daytime. A prompt removal prevents humidity buildup and allows the plant to access the sun’s heat.

Our Pick
Plant Covers for Winter Frost Protection With Drawstring
$12.99

These soft cloth plant covers keep your plants safe during cold temperatures. The cloth is also breathable and allows plants to get sunlight and perform photosynthesis. The pack contains two plant covers of around 72-inches by 72-inches.

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We may earn a commission if you make a purchase, at no additional cost to you.
08/11/2022 01:36 am GMT

Can You Use Cardboard Boxes to Protect Plants From Frost?

Yes! A cardboard box can give perfect protection against frost. Cardboard has good insulating properties and will keep your plants warm and safe overnight. Choose a cardboard box that is larger than your plant. Sit the box over the plant’s top, and secure it in place with rocks or bricks. Make sure to monitor for and remove snow from atop the box.

Can You Use Towels to Cover Plants From Frost?

If the plant is small enough, then sure! Old towels can be repurposed and take on a new lease of life as a frost cover for plants! Any fabric, such as old bedspreads, will also work well. I love using old pillowcases to tuck up my smaller shrubs at night.

What Is a Frost Blanket for Plants?

If you are in a high-risk zone for frost, you might want to consider investing in a few frost blankets. These durable and lightweight garden fleeces can be draped over young seedlings or used to create a cloche with the help of plastic hoops. They work to shield young tree saplings and give powerful protection against pests, too!

The best thing about a frost blanket? Unlike other frost protection solutions, it stays in place at all times. This convenience factor saves a lot of time every day. It also means you don’t have to panic every time a frost is forecasted!

Conclusion

Homesteading is a rough business – whether you endure sweltering heat or frigid winters!

If you struggle to keep your plants alive during the deep overnight frosts – then covering them helps!

You can cover your plants with trash bags to keep them alive. But remember – don’t let the plastic come into contact with your plant!

We also recommend using a cloth cover in most cases.

If you have any questions about covering your gardens, shrubs, or plants over winter – let us know!

We have tons of experience gardening in all climates – and protecting all manner of plants from the cold. 

Plus, we love hearing from you.

Thanks for reading!

Read More – How to Improve Garden Soil Over the Winter!

Author

  • Kate moved to Portugal last year and lives with her husband, two cats, six hens, and a glorious Brahma rooster called Mary. Earlier this year they purchased a half-hectare ‘quinta’ – traditional terraced land with olive trees, grapevines, and a house to renovate. They are currently living in a small campervan which is a challenging but fun experience! Kate has over 15 years of experience in the UK veterinary industry and is also a passionate gardener – turning a grassy field into a productive vegetable patch in just three months. Future plans include more animals, particularly sheep and goats for milk production to make cheese, butter, and yogurt! Kate and her husband are aiming to create a self-sufficient off-grid life on their quinta, fulfilling a life-long dream.