Sheltered Ground

special places or plots used to grow seedlings of vegetable, flowering, forage, and industrial crops as well as vegetables, flowers, and fruits. These plots make it possible to raise vegetables and fruits in the north and east, enlarge the variety of crops grown in a particular locality, and organize the year-round supply of fresh vegetables. Sheltered ground is subdivided into various types of installations and places for growing things. The very simple types include unheated soil (seedbeds, ridges, cold frames, and plots with a level surface covered on cold nights with heat-insulating materials impermeable to light or covered throughout the cold weather period with transparent materials) and heated soil (installations with biological or water heating). Hotbeds and greenhouses provide better kinds of sheltered ground.