What is a greenhouse used for?

Answer 1

They don't. Only gardeners, nurserymen, and horticulturists use greenhouses, not farmers. Farmers or crop producers make use of what's already being provided in the natural world (sun, soil, weather, etc.) to grow their crops.

Answer 2

In some countries, during the winter months, the temperature is not so much high that the plants can grow properly.So, the crops are grown in the glasshouse for maintaining the warm temperature for them. Examples are tomatoes and cucumbers require warm climate in the glasshouse.

Answer 3

Crops grow better in green houses because the glass or plastic the green house is made from acts like the ozone layer around the Earth in a way in which it lets heat in but not out keeping the Earth warm and the plastic/glass that makes the wall of the green house keeps the plants inside warm. All plants need the basic things which are food, water and heat but some plants need more heat than others so if you wanted to grow tomatoes in the middle of winter then you would need to put it in a green house.

Answer 4

It allows the growing, either of native crops earlier than normal, or allows the growing of plants not hardy in the area.

Answer 5

Refrigiration. Like Greenland, greenhouses are not actually green but rather covered in snow whereas Iceland is ironically totally green.

Answer 6

They don't make small enough combine harvesters, that's a definite disadvantage :)