Why Garbage Bags Won't Protect Your Plants From Frost (& What To Do Instead)

If you're worried about frost damaging your plants, covering them can be an excellent solution. Frost can form even before air temperatures drop below freezing. And when the air temperature drops below freezing, plant cells freeze and die. Although frost will not cause as much damage as a hard freeze, you should prepare certain plants ahead of cold weather. Despite its convenience, there's one item you should stay away from to cover your plants. If you're looking for tips for protecting your plants from frost, avoid using garbage bags as plant covers.

Trash bags are not the best protection against frost damage, primarily due to their material. Most garbage bags are made out of low-density polyethylene plastic. Placing plastic around your plants increases the risk of cold damage or burning, because the material will transfer heat away from the plant. Plastic also does not offer the breathability your plants need during cold weather. This means that the bags easily trap moisture that can freeze to the plant instead of protecting it, if the temperature drops low enough.

Instead of garbage bags, choose a material that provides good insulation and air flow, like cloth. A variety of cloth covers can be placed over plants before an anticipated frost. Professional landscape services recommend materials designed for frost protection, such as frost fabric or row covers. You can also use old blankets, towels, and sheets if you have nothing else on hand, but heavy items should be used on sturdy plants along with stakes to protect branches and foliage. It's also fine to use burlap as an easy and affordable way to protect young trees from frost damage because it is both breathable and durable. Also, remember to remove frost protection during the day when air temperatures get warmer.

Ideally, the best covers do not touch the plant at all. You can accomplish this using a combination of stakes, posts, and other items you have on hand. Ensure that whatever type of cloth you choose to cover your plants is secured firmly. You don't need cold winds to carry it away or get under the cloth to damage your plant. The goal of a cover is to trap heat from the soil inside, not to let it escape. It's also good to plan ahead by learning how to find the first frost date for your garden where you live and preparing proper coverage for your plants — just remember to stay away from plastic garbage bags.