While it is always advisable to apply whatever fertilizer is used before plowing, commercial fertilizers can be applied later with good effect; but it will be necessary to apply them in such a manner that they do not come directly into contact with the seed, as many of them are so strong that they kill it.
Plow the garden deeply, for by so doing you bring to the surface a stratum of soil in which there is more latent fertility than in that close to the surface.
After plowing, allow the soil to remain as thrown up from the furrow for two or three days. Sunshine and warm air will have a disintegrating effect on it, which will make it easy for you to reduce it under the application of hoe and iron rake to that mellow condition so necessary to the welfare of the plants you propose to grow. It should be worked over and over until not a lump is left in it. You cannot expect to grow good vegetables in a soil that has not been well pulverized before seed is planted. Large grounds, or those of a size that admit of the use of horses, can be speedily mellowed with the harrow, which should be run over the ground from all directions until it is thoroughly pulverized. In the small garden the rake and hoe will have to take the place of the harrow.
Small pieces of ground should be spaded. Let the soil remain as thrown up by the spade for two or three days before attempting to work it.
I have been told by some amateur gardeners that they did not use much manure because trees and shrubs that grew in close proximity to their gardens were so thrifty without manuring that they felt confident that the soil must be quite rich enough for vegetables without resorting to the use of any fertilizer. These persons lacked the experience which would have enabled them to understand the wide difference between tree and vegetable growth. A tree or a bush sends its roots deeply and widely into the soil, and applies to its uses food that the vegetable cannot send its roots in search of. The roots of most garden plants do not extend far in any direction, nor go very deep; therefore food must be given directly to them if we would secure the best possible result. There are very few gardens in which the natural soil has a sufficient amount of nutriment to produce the effect we aim at without the addition of some kind of plant-food.