Bubble wrapping is the most common method used by gardeners to insulate their greenhouse over the winter. Eli gives some advice on the how and the why.
Something all greenhouse owners have in common is the great satisfaction that comes from a greenhouse in summer. During the warmer months, your greenhouse is a great way to save energy. Sunlight comes in and quickly warms up the inside, making it the perfect place for your plants. However, during the colder months, we greenhouse owners are ripped apart into two camps – heated and unheated.
The sun doesn’t give off much warmth in the winter, and in some parts of the country, there may not even be much direct sunlight. For this reason, gardeners use a wide range of techniques to keep the greenhouse as warm as possible and keep tender plants safe from frost. Bubble wrap is a common solution but for new gardeners, it can be a daunting task. Let me ease some of your fears by giving you more information and some useful tips on how to bubble-wrap a greenhouse.
As temperatures start to drop, many gardeners look for ways to extend the growing season in their greenhouses. One popular solution is to use bubble wrap insulation. Bubble wrap provides an extra barrier to retain precious heat during colder months.
In this comprehensive guide we’ll cover the benefits of bubble wrap for greenhouses, optimal installation techniques alternative insulation options, and tips to make the most of this simple yet effective method.
Why Use Bubble Wrap for Greenhouse Insulation?
Bubble wrap offers several key advantages as insulation for greenhouses
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It’s an affordable, accessible option available at most hardware stores.
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The plastic wrap adds a protective layer without blocking light like some materials.
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Bubble wrap is lightweight and easy to install each season.
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It effectively traps heat rising within the greenhouse, acting like double glazing.
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Bubble insulation is a passive system requiring no energy input.
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It’s a temporary solution that can be removed and stored during warmer weather.
Selecting the Best Bubble Wrap
While regular packaging bubble wrap can work, it’s best to use horticultural bubble wrap designed for greenhouse use. Key features:
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Larger air pockets provide better insulation.
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It’s UV-resistant to withstand sun exposure over multiple seasons.
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Some types have a reinforced backing for durability.
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Options like double-layer “twinwall” bubble wrap offer even more heat retention.
For the greatest insulation value, look for greenhouse bubble wrap with the thickest bubbles possible. Also choose a width that allows you to cover surfaces smoothly and seamlessly.
Installing Bubble Wrap Insulation
Proper installation ensures your bubble wrap insulation performs optimally:
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Clean all greenhouse glazing to maximize light transmission before installing bubble wrap.
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Measure surfaces and cut bubble wrap to fit using a sharp utility knife. Avoid excess wrinkling.
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Attach the bubble side against glazing for best heat retention.
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Start at the top and overlay strips by 2-3 inches, sealing with greenhouse tape.
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Use clips, fasteners or tape specially made for greenhouses to secure the bubble wrap.
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Look for gaps where heat could escape and double up insulation in those spots if needed.
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Add small vents at the top to allow humidity to escape and prevent condensation.
Alternatives to Greenhouse Bubble Wrap
While bubble wrap is a top choice, other options exist for insulating greenhouses:
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Polyethylene sheets – Lightweight and inexpensive but not transparent.
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Insulated curtains – Help retain heat at night but block light so best for outer layers.
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Rigid foam panels – Provide excellent insulation and some light transmission but more expensive.
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Fleece fabric – Traps heat when used as an inner layer but opaque so needs vents for light.
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Fan heaters – Actively warm the greenhouse but use electricity increasing operating costs.
Tips for Using Bubble Wrap Effectively
Follow these tips to make the most of bubble wrap insulation in your greenhouse:
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Use an additive like WaveLength Selective film to boost light transmission through the plastic.
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Add an additional layer of bubble wrap over vulnerable plants or on extremely cold nights.
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Maintain temperatures inside between 50-60°F for optimal plant health during cooler months.
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Monitor humidity levels and add or enlarge vents as needed to prevent excess condensation.
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Remove insulation on sunny winter days when the greenhouse warms up sufficiently to prevent overheating.
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In spring, remove the bubble wrap promptly to avoid trapped heat damaging tender new growth.
Enjoy Season Extending Benefits
Adding an insulating bubble barrier is a simple, affordable way to retain heat and extend the growing power of your greenhouse. With proper selection and installation of greenhouse-grade bubble wrap, you can keep your greenhouse garden going strong during cool weather.
Follow best practices for installing and monitoring your bubble wrap insulation. Combine it with good ventilation and ideal temperature maintenance, and your plants will continue thriving past summer. The extra weeks or months of growth can make bubble wrap a very valuable addition!
How to bubble wrap a greenhouse
This is best done after the annual clean. Clear out all the cracks and make sure the glass is clean. Also, make sure that the whole building is free of dirt, bugs, and disease. Give the greenhouse a chance to air and dry after cleaning. Since you won’t be able to open the windows or vents once the greenhouse is wrapped, it’s important to get rid of the moisture inside.
Eli washing exterior of greenhouse
Choosing your bubble wrap is important. Packing bubble wrap will offer little insulation and will deteriorate when exposed to the elements and sunlight. Horticultural bubble wrap that is made to last two or three seasons is thicker and has been treated to protect it from UV damage. It is important to consider the longevity whilst we all do our best to reduce our single-use plastics.
Kate starting on the upper area with the bubble wrap
Now for the fun part. Long sheets that aren’t cut or joined together too much are the best way to bubble wrap the greenhouse so that less heat is lost. I’ve found that long lengths wrapped horizontally from one side of the door around the greenhouse to meet the other side of the door frame at ground level work best. Sticky tape or small plastic greenhouse pegs that fit into the channels in your greenhouse frame can be used to hold the bubble wrap in place as you go.
Plastic pins for attaching bubble wrap to greenhouse interior
When it comes to wrapping the roof, you might need to get creative with the wrap. This is where having a willing helper comes in handy.
Kate affixing bubble wrap to the roof and vents
Why bubble wrap a greenhouse?
The purpose of adding bubble wrap is to provide a layer of insulation. But horticultural bubble wrap is better than the usual kind of packaging.
Not only is horticultural bubble wrap thicker, the bubbles inside are also bigger. It’s the air pockets inside the bubbles that keep the heat in. The way double glazing works is the same: it puts an air pocket between two panes of glass to slow the flow of heat and cold. Putting bubble wrap around the greenhouse is meant to keep any useful heat inside during the day and keep frost from getting in at night. This insulation can raise the temperature inside the greenhouse by one or two degrees, which is a pretty big deal!
How to insulate a greenhouse with bubblewrap
FAQ
Can I use bubble wrap to insulate my greenhouse?
What is the best insulation for a greenhouse?
Which way does bubble wrap go in a greenhouse?
Is bubble wrap a good insulator for plants?
Should you use bubble wrap in a greenhouse?
Regular bubble wrap (the kind that you can pop between your fingers) won’t provide sufficient insulation. Energy curtains can help you minimize temperature fluctuations in your greenhouse. Also known as thermal curtains, they provide an additional layer of insulation that prevents thermal loss during the night.
Which bubble wrap is best for greenhouse insulation?
It typically is only single walled and will not insulate nearly as well. So you definitely want to use a horticultural grade bubble wrap. This will be the best bubble wrap for greenhouse insulation. In addition to keeping your greenhouse warmer during the winter months, it can also help you save on cooling costs when it’s warm.
How do you make a greenhouse with bubble wrap?
Ensure you have bubble wrap, scissors, a measuring tape, and fastening materials (e.g., velcro, magnetic strips, gorilla glue). Measure and cut the bubble wrap to fit the interior panels of your greenhouse from floor to ceiling. Aim to use long, continuous bubble wrap sheets, minimizing cutting and joining to reduce heat loss.
How do you install bubble wrap insulation in a greenhouse?
Greenhouse insulation fixing clips can hold your bubble wrap in place, or you may be able to put fixing screws directly into the channels in your Greenhouse’s aluminium extrusion, without causing any damage. Read more about how to install bubble wrap insulation in a Greenhouse.