The Right Time to Harvest and Store Onions

Ancient names for this plant in Sanskrit, Hebrew, Greek and Latin are apparently unrelated, an indication of widespread cultivation dating to prehistoric times. Ancient methods for harvesting and storing were probably not greatly different from those used today. For best storage, the onion must be thoroughly mature and dry. When the onion plant is mature, the top falls over and turns yellow. When about 95 per cent of the plants have fallen down, it is generally time to harvest the crop.

Certain stairs of the Sweet Spanish variety do not turn yellow, although bulbs are mature. When in doubt, pulling and inspecting a few bulbs can indicate maturity if the skin of each bulb is mature and dry. When the onion plant falls over, the neck has closed and the plant has matured. A closed neck is important for longest storage. Some gardeners feel that bending over onion plants that have not fallen down may help the neck to close. However, it is generally believed that this does little good, and perhaps it would be better to sort out plants that have not broken down and put them aside for prompt use.

Onions are harvested by pulling and piling the bulbs from several rows into a windrow with the tops covering the bulbs for protection. Bulbs should not be exposed to direct sunlight, especially when temperatures are quite high. High temperatures can injure tissue close to the surface and reduce storage life of exposed bulbs. If the planting is not large, the bulbs should not be left in the garden, but taken directly into a shed, porch or other protected spot to be spread out and to dry for a few days.

After drying, the tops should be clipped off one-half to one, inch above the bulb. At this point, onions with thick necks or seed stalks should be sorted out for prompt use, as they will not keep well. Onions must be thoroughly cured before placing in final storage. Drying normally takes 2 to 4 weeks and must be done in a dry, ventilated place. Spread them only one layer deep on newspapers or on well ventilated shelves.

Larger quantities may be placed in slatted crates in an open shed. Good ventilation and air movement around the bulbs must take place at all times. A fan can help to move warm air among the bulbs in boxes. After the onions are thoroughly dried, any showing rot or damage should be removed and the bulbs moved into storage for the winter. The storage area should always be above freezing, but fairly cool and dry. Low humidity is important for best storage.

Mesh bags, such as those used for selling citrus fruits, are ideal storage units for onions. During the winter, check occasionally for any that may develop rot Soft or rotten bulbs should be removed to prevent spread to nearby solid bulbs.

http://en.wikipedia.org/wiki/Onion