Preventing Freezing in your garden

Q. I have a farm in Afghanistan, which is about 30,000 square meters (3 hectares, or 7.5 acres), in which mainly grapes are grown. In the cold winter the grape vines are buried under the ground because of the very cold weather and then in the spring the vines are exposed to air and light, then the vines become green.

Mostly this works, but in some years, after the plants grow their leaves and grapes, the weather becomes cold again for only one night. All the grapes freeze and become black in color, and there is no time for the plants to grow new fruits because of the arrival of the winter.

Is there any solution for this problem other than a green house, because it will be too expensive to cover all of the farm. Is there a way to warm the plants for one night only? This year the whole yield of grapes was frozen. Please help.

A. 1) Watering everything, including the ground as well as the entire plant, immediately before it freezes, can sometimes save a crop if the frost is not too hard.
2) Another solution may be to have many small fires burning throughout your vineyard during the time temperatures go below freezing. In America this is done with propane and kerosene heaters, but that would probably be too expensive for you. We also use fans to blow the warm air throughout the orchard,
garden, or vineyard.