How To Use Bubble Wrap To Protect Your Garden From Frost
When a surprise frost is headed your way, you may start scrambling for something to use to protect your plants from damage. If you have a stash of bubble wrap, you are in luck! While plastic alone is a decent insulator, those air-filled pockets can give your plants an extra layer of protection against cold temperatures.
The key to using any kind of plastic as frost protection in the garden is not allowing the plastic to touch any part of the plant, states Green Impressions. Moisture can get trapped beneath a layer of plastic, and when that moisture freezes, it can damage tender plant leaves. When you use bubble wrap to protect your plants, make sure you leave plenty of room around the plant, so it does not get damaged, and remove the plastic as soon as the possibility of frost has passed. Leaving a plant wrapped in plastic can suffocate it, or if your frosty night is followed by a sunny day, the plastic can create a greenhouse effect, essentially cooking your plants. Don't let these warnings scare you. When used correctly, bubble wrap can save your garden plants from frost damage.
Container plants
Container plants are more susceptible to the damage caused by cold temperatures because they do not benefit from warmth retained in the ground. Soil absorbs heat from the sun during the day, which helps protect in-ground plants (via Michigan State University Extension). Conversely, although containers are filled with soil, any heat retained in the planter is quickly released through the top and sides when temperatures drop.
To protect your container plants from roots to tips, wrap the entire outside of the container in bubble wrap, starting at the base. Prevent the plastic from touching tender green leaves using whatever you have available. You can use tomato cages, wooden stakes, or extra PVC pipe as a frame around which you can safely wind bubble wrap. Be sure to cover all sides and the top, so there are no holes. If you have extra bubble wrap, a second layer adds more frost protection. Secure the sheeting with duct tape so it cannot blow off.
In the garden
For in-ground plants, you can use the heat slowly released by the soil to create a mini greenhouse using bubble wrap. Like container plants, you will need to make some kind of frame around your plant so the plastic does not touch any green parts. If you need to protect an entire row of plants, consider creating a mini greenhouse using PVC hoops, like this one from Bonnie Plants. Although they use frost blankets, you could easily use bubble wrap as an insulated covering.
To protect a few small plants from frost, head for the recycle bin to find empty milk jugs or two-liter bottles. Cut the bottom off and place it securely over each plant, pushing it slightly into the soil. This will allow the warmth of the soil to escape into the mini-greenhouse. Cover each bottle with bubble wrap secured with duct tape for an added layer of frost protection.