It is the most basic guarantee for growing vegetables to get sufficient sunlight in greenhouse cultivation. Therefore, the construction of vegetable greenhouses must choose a site with sufficient lighting conditions.

         The shaded objects such as buildings and trees facing south of the greenhouse construction base should be no less than the shaded objects from the front feet of the frontmost greenhouse. The highest shaded point is the length of the shadow projected in the afternoon of the "winter solstice".

         The distance from the southeast or southwest direction of the greenhouse base to the front feet of the front row greenhouse should be no less than twice the length of the highest shade point of the shaded shadow projected at noon of the "winter solstice".

         This kind of greenhouse construction is the most reasonable, and can meet the ventilation and lighting conditions of vegetable cultivation.