This section is from the book "Vegetable Gardening", by Ralph L. Watts. Also available from Amazon: Vegetable Gardening.
A few years ago greenhouse growers thought it essential to provide benches with bottom heat for practically all greenhouse crops, but the opinions held today are different. In many of the largest and most successful houses there are no benches or even beds with board, brick or concrete sides. These mammoth houses often have large doors at the ends so a horse and cart can enter with manure or other supplies. It is also possible to use plow and harrow in the preparation of the soil for planting. While all greenhouse growers do not approve of horse tillage under glass, some of the most successful growers always use horse implements in preparing ground for the fall crop.
Benches are convenient in the handling of flats and potted plants, but they are expensive to construct and maintain unless made of concrete.
Solid beds, with or without sides, provide more uniform soil conditions than do shallow beds. There is less danger of injury from improper watering and, therefore, the chances of success are increased. Solid beds are especially advantageous when the watering must be intrusted to men of limited experience.
The walks should be arranged so that all the beds can be cared for conveniently. Beds or benches 5 feet wide and walks or alleys 18 inches in width make a desirable combination, although the relative width of beds in commercial houses is often much greater. As plants do not do well next to the walls, it is desirable to have walks there, and the house space can then be divided in such a manner as may seem convenient for the care and harvesting of the crops to be grown.
 
Continue to:
plants, crops, gardening, cultivated, harvesting, food ,greenhouses, fertiliser, vegitables