Outdoor plants are sometimes susceptible to cold temperatures. In times when buds are new or flowers are popping out, a freeze sets back the process. There are several ways that gardeners and other growers fight off the cold weather, such as heaters and fans, but one of the easiest methods for smaller vegetation is to cover them. This blocks wind and frost so that it can't damage the plants.
Lower a small bag such as a plastic grocery bag over small plants to insulate them and keep frost from settling. Be careful not to bend stems or leave any of them outside of the bag.
Lower garbage-size bags over medium-size plants. Cover the entire plant if at all possible.
Wrap larger plants with sheets of plastic. Use tape to connect sheets of plastic if needed. This will seal gaps that could let air and frost in. Wrap around the plant from the top down, then wrap around the trunk.
Secure all coverings. Use twist ties or zip ties to secure the wrap to the base of the plant. This will anchor the covering so that it doesn't blow off as well as keep the winds from getting up in the plant.
Cover soil around the base of the plant with mulch to insulate the ground and keep it warm. The mulch will also release nutrients into the dirt to feed the plants and retain moisture so that the plants will not lose water.