Most fall gardens are planted with what is called Cole Crops. Cole Crops grow best at monthly average temperatures of 60 to 70 degrees F. Every once in a while, we get an unusual cold snap here in north Texas. In February of 2011, the temperatures got as low as 10 degrees F. In extreme weather, you can protect your crops by insulating them with 3 to 6 inches of straw over the entire plant.
Frost blankets are another good option for protecting plants from extreme cold temperature. Frost blankets (also called floating row cover) are also used in conjunction with frames to protect plants. Frame material can be PVC pipe, wood or steel. Simply construct the frame over the row of plants and lay the frost blanket on top of the frame. I have heard of some folks placing lights and heat lamps under the blanket in extreme conditions. If at all possible do not lay the blanket on the
Precautions should also be taken with the ornamental plants. Now is not the time to apply high nitrogen fertilizer. This is where the all-natural fertilizers really shine. All-naturals are somewhat slow release, very efficient and they do not cause rapid growth like some of the synthetic fertilizers. Pruning should only be done when the plant is in, or close to dormancy. Pruning plants too early will spur new growth that can be damaged by the cold.
Over Winter: http://aggie-horticulture.tamu.edu/newsletters/hortupdate…/hortupdate_archives/2002/jan02/art3jan.html