Frost forms as a result of the surface of some object being chilled below the dew point of the surrounding air. The dew point is the temperature at which air must be cooled in order to be condensed into water. When the chill point is met crystals form on the surface of the object and appear as ice.
The most common form of frost on vegetation is Hoar Frost also known as Radiation Frost. This occurs when ice crystals form overnight due to drops in temperature and heat loss because objects become colder than the surrounding air.
Many plants can be damaged by the affects of frost and some, such as tomatoes, will die. To know which plants will survive a cold night, refer to the back of the package of seeds that you bought as they have excellent instructions as to temperature ratings.
If you bought your plants already grown from a nursery or garden center then it is best to check with someone there so you do not plant them too early. However in a moment I will talk about protecting your plants in the event an unseasonable frost should occur.
The United States Department of Agriculture has an excellent map on first and final frost dates for various regions of the U.S. They have broken the country down into zones. Find your zone and you will be able to calculate when you should start planting your vegetables.
Even with the best calculations sometimes Mother Nature just doesn抰 cooperate. As was the case in May of 2009 when three weeks into the month frost conditions occurred in the southern New Jersey and eastern Pennsylvania regions.
Until there is a consistent level in temperatures you should monitor the overnight conditions in your area which can be easily done by watching your local weather or the weather channel. If you have planted your vegetables and they call for a potential of frost, you can and must take precautions to ensure that they, your vegetables make it through the night.
The best method for protection from frost conditions is the use of plastic milk containers. What you want to do is cut the top of the container off, but not too much so the plant won抰 fit, and cover the plants with them. This creates a greenhouse warming affect for your plants. The container traps air which stays a constant temperature, never allowing it to drop below the dew point and create frost for the surrounding plant.
When morning comes and the cool temperatures have subsided for the day, remove the plastic milk containers and let them soak in the sun and air. They should be fine.
For gardeners, frost can be a devastating condition and literally wipe out any growth we might have. But there are remedies, actions and preventions we can implement that will increase our chances of success through frost weather conditions.
