The bed sheet and plastic trap ground heat and act as a greenhouse.
It’s not complicated.
Just make a tiny greenhouse!
Lock in the Moisture
Start with a piece of burlap or sheet plastic. A square shape that isn’t too big and bulky is a plus. Wrap the plant tightly with clothes pins, string, or bungee cords. The tighter the better.
If the plant roots are inside a container, like a clay pot on a patio, lay the plant sideways so it’s closer to the ground. Cover the container and plant with plastic or a bedsheet. This protects the roots by trapping the small amount of heat coming from the ground. The ground temperature is higher than the cold air and the plastic or covering will trap the heat like a greenhouse.
After the temperature rises above 32 degrees Fahrenheit and remains so, remove the covering. The plant most likely will survive this cold snap and get stronger next year.
This Winter protection isn’t necessary if the tree or shrub is planted in the ground and is cold hardy. Cold hardy is determined by a zone number. Most plants in your area are cold hardy. This means their cold hardiness zone is equal to your climate zone or colder. For Tennessee, that’s zone 6, 7, and 8.
