By W.R. Beattie, USDA Bulletin 1909
As with so much of the older reprint material we offer, you are encouraged to do your homework and make sure that the practises are suitable for your region and farm, as well as meeting whatever standards you have chosen to adhere to. SFJ
INTRODUCTION The onion is one of the important market-garden and truck crops in the United States and is very generally grown in home gardens. It thrives best on alluvial and drained muck soils under a temperate climate, but may be grown under a very wide range of soil and climate conditions. Onions are grown to perfection on the alluvial soils of the Nile River Valley in Egypt, under the sea breezes of the South Sea Islands, on the delta lands along the sea coast, on sandy uplands, in the aridregions under irrigation, and on reclaimed swamp lands. There is perhaps no extensive area in the United States or its possessions where the onion, in one or more of its forms cannot be successfully grown, at least for home and local use.
The onion is of Old World origin and has been used as a food plant from the earliest historic times. It was an important article of diet in Egypt at the time of the building of the pyramids, and Moses, in his account of the exodus of the children of Israel from Egypt, mentions it as one of the articles of food for which the Israelites longed for during their sojourn in the wilderness.
Onions were brought to North America by the early discovers and became one of the common crops of colonial gardens. Commercial onion culture in its present form has developed mainly during the last 40 or 50 years. Formerly the production of onions for sale was confined principally to the New England States, but the industry soon spread to other sections, and when the vast muck areas of the Great Lakes and other regions were drained and brought under cultivation the onion soon became one of the most important crops on these soils.
At present the principal commercial onion-growing centers are located in New England, especially in the Connecticut River Valley, in northern New Jersey, southeastern New York, the entire Great Lakes region, and as far west as Minnesota. The production of Creole onions centers around New Orleans, La, and the greater part of the Bermuda-onion crop is grown in southwestern Texas and in California. Within the last few years the production of the Sweet Spanish onion has developed in several of the Western States, including New Mexico, California, Arizona, Utah, Nevada, Washington, and Oregon. In addition there are many local areas in the United States where onions are being grown in considerable quantities for the market.
The production of several crops closely related to the onion, such as chives, shallot, leek, and garlic, has been developed around local centers, especially in connection with market gardening near the large cities. Garlic might be mentioned as an exception, because it is produced mainly in a few localities where soil and climate are especially suitable for its growth.
CLIMATIC REQUIREMENTS For best results a temperate climate without great extremes of heat and should be selected. Onion culture is rarely profitable in regions where the climate does not change or has no definite seasons of heat and cold or moisture and drought. The onion does best under rather cool conditions, with plenty of moisture during its early stages, but requires a reasonable degree of heat, together with dryness of both soil and atmosphere, for its proper ripening. Where the onion industry has become established in the extreme southern part of the United States, the growing season is during the late autumn and winter, the crop maturing during the spring and early summer. If the crop matures at a time when there is considerable rainfall, it will be impossible to cure the bulbs without artificial means and they will be lacking in keeping qualities.
Certain types and varieties of onions, including the top onions and the multipliers or potato onions, are extremely hardy and may remain in the open ground throughout the winters of our Northern States, especially if given slight protection. These types are, however, not adapted to growing for market, except as green onions, “peelers”, or “bunchers” to be sold during the early springtime. In certain sections of the South Atlantic coast region large areas of the top multiplier onions are grown for this purpose. There is also a marked difference in the day-length requirements of the standard commercial sorts, some being adapted to growing far northward, while others, like the Bermuda and Creole types, do best in restricted southern localities.
The period required for the production of a crop of onions will depend upon the season, the methods employed in growing, and in the variety. If grown from seed, a period of from 130 to 150 days will be required. If from sets, the crop often may be matured in 100 days. If grown in the extreme northern part of the United States, where seasons are short, the crop will mature more rapidly to the southward. In the case of the Bermuda onion, as grown in Texas, the growing season extends from October to the following March or April.
Onions require an abundance of moisture during the early stages of their growth, but should be ripened under comparatively dry conditions. In most sections the seed is sown at a time of year when frequent spring rains occur. Their period of greatest growth is during the early part of the summer, and the crop is ripened late in the summer when drying conditions may be expected. In irrigated regions the application of water is almost entirely under the control of the grower. During the active period of growth the water is applied about once a week, the soil being thoroughly soaked and the surplus water drawn off.
The amount of rainfall or irrigation required for the production of a crop of onions will depend largely upon the character of the soil and its drainage. Many of the peat or muck soils in which the soil water remains near the surface will require very little rainfall; in fact, the best crops of onions are produced on these soils during seasons of comparatively light, but evenly distributed rainfall. Sandy and loose soils generally require a greater amount of water, especially during the early part of the season.
SOILS ADAPTED TO ONION CULTURE The essential requirements of a soil upon which to grow onions profitably are a high state of fertility, good mechanical condition, properties – that is, if it contains sufficient sand and humus to be easily worked, is retentive of moisture and fertilizers, and is capable of drainage – all other requirements can be met. At least three types of soil are being extensively planted to onions in this country, the one common essential being proper mechanical condition.
Clay and alluvial soils abound in the river valley and delta regions near the coast. These soils are generally very fertile, but may require the addition of humus or stable manure in order to lighten them. The greatest difficulty encountered in growing onions upon land of this character is the tendency of the soil to run together and bake after hard rains. This is especially injurious after the seed has been sown and before the small plants have attained sufficient size to permit of stirring the soil about them. Where those soils contain considerable sand they are ideal for onion culture. Soils of this type are easily injured by plowing or working while wet.
Sandy soils, especially where underlaid by a well-drained clay subsoil are often well adapted to onions. Soils of this character generally require heavy applications of fertilizers before they will produce a paying crop, but the quality of the product is excellent. Onions grown on sandy loams are generally solid, heavy, and of excellent keeping quality. Where sandy soils are lacking in humus this may often be applied by means of crops of legumes grown upon the land and plowed under.
Throughout the north-central part of the United States and the delta region of California there are vast tracks of peat and muck soils that are being utilized for the production of the commercial onion crop. Before planting to onions, however, these soils must be cleared, drained, and brought to a suitable state of cultivation. In many cases this process will require two or three years’ time, but sometimes the soil can be broken during the early winter, allowed to lie exposed to the action of frost, then worked down and planted to onions the following spring. The store of plant food in muck soil is usually large, but often it is not in available condition, and heavy applications of manure (and/or commercial fertilizers, especially super-phosphate and potash), are essential to profitable crops.
CULTURAL METHODS The onion belongs to that class of crops that gives best results under very intensive culture, and the greatest yield are secured where a moderate acreage is planted and the work conducted in a most thorough manner. There is nothing technical about the growing of onions, but close attention and frequent cultivations are essential. Once the weeds get a start, the cost of production will be greatly increased, or the crop may be lost altogether.
PREPARATION OF NEW LAND As a general rule new land is not adapted to onion growing until it has been worked one or two years with other crops. Onions should follow some row crop that has been kept free of weeds the previous season. Corn, beans, and potatoes are suitable crops with which to precede onions. Muck and sandy soils may in some cases be brought to a suitable condition for onions the first season, but the fitting will have to be thoroughly performed. The land should be plowed in the spring, after which numerous harrowings and doubtless some hand work will be required to get the soil in suitable shape.
If necessary to manure the land heavily before planting to onions, it will be desirable to plant to some farm crop one season, then apply the manure during the autumn in order to give it time to become incorporated with the soil. Owing to the value of good onion land it would be advisable to devote it to general farm crops for any extended period, although corn is frequently planted and oats or rye are sometimes used in the North. Cowpeas may be of great service in bringing new land into shape for planting onions.
CROP ROTATION Onions should not be planted on the same piece of land year after year, but some system of crop rotation should be maintained. Care should be taken, however, to use crops in rotation that will not be exhaustive of the high fertility necessary in the onion land. During the years when the land is not devoted to onions it can be planted to some truck crop that will give a return that will justify the applications of large quantities of fertilizers, or, better, to a leguminous crop to be turned under as green manure. Continous cropping with onions will cause the land to become infested with both disease and insect enemies that will sooner or later injure the crop to such and extent as to render it unprofitable.
PREPARATION OF THE SOIL Assuming that the land intended for planting to onions is capable of being brought to a good mechanical condition, is fertile, well drained, and reasonably free from weed seeds, the first step in the production of the crop will be to plow moderately deep, then harrow, disk, roll, and drag until the soil is smooth and mellow to a depth of 5 to 7 inches. The method of preparing the soil will depend some what on the character, the manner of planting to be followed, and the requirements for irrigation. There are few truck or other crops that require so careful fitting of the soil as do onions, and it is essential that the fertilizers be well mixed with the soil.
On soils that are naturally well drained and where surface water can not accumulate, the plowing may be done in large blocks, but where the opposite conditions are found or irrigation is practiced it may be necessary to plow the land in narrow beds. In the case of insufficient drainage it will be desirable to throw the soil into beds, leaving double furrows between the beds to carry off surplus water. Where the flooding system of irrigation is practiced the beds must be leveled and a system of ditches and ridges provided for distributing and controlling the water. Where it is merely desired to secure surface drainage the beds may be from 75 to 150 feet in width, but for irrigation purposes the beds are generally but 12 or 15 feet in width. If spring plowing is practiced the soil should be harrowed closely behind the plow in order to prevent drying out.