Frost damage to the plants is serious in some regions.
You can save your plants by trapping the heat radiated from the ground with a plastic or similar material and moving your plants to a sheltered location, if possible. Use of light bulbs is also recommended to give some heat to the plants.
Moreover anti-transpirant sprays can be used to give two to three degrees of protection to your plants. Don't forget to water your plants even in cold season.
Some other methods to protect your plants.
Protect your tomato plants:
Green caterpillars are the most common pests in tomato garden. They are not dangerous to human but very lethal for your tomato plants. You can save your tomato garden in following ways:
Till the soil at the end of each gardening season, it can be perfect way to prohibit the growth of pests that destroy your garden.
Handpick those caterpillars, they do not bite. It can be useful, if you have a small tomato garden and patience. Just put them in soap solution and they are dead.
BT or bacillus thuringiensis is a powder, can be sprayed on the leaves after mixing it with water. It kills other pests and larvae that feeds on them.
Another way is, you can wash your plants with a stream of water to wash them away. But this advisable, only when you have a good drainage system available in your garden.
Save your pepper plants:
Make your own pepper spray repellent. Mix two teaspoons of cayenne pepper, one quarter of water and soil solution. Now put the solution in a bityle , apply it on first few plants to see any negative reaction. Reapply it after a heavy rain.
Another way, is to grow companion plants which are repulsive to insects. Plants like Marigold, garlic can be grown.
Friend, dont worry I will come with a new hub explaining the theories of protection of plants from insects.